Thomas Tuchel had every reason to be bitter, but it was hard to argue with his assessment: VAR has a handball problem. The decision to penalise Presnel Kimpembe on Wednesday night was the latest example of a referee convincing himself, after watching enough slow motion replays, that deliberate handball had been committed. Even when in real time it was far from obvious.

“I am a big supporter of VAR, and I still a big supporter of VAR,” Tuchel insisted at his post-match press conference at Parc des Princes. “But with handball, it is a super-difficult thing. Because there are too many points in do we punish it or not punish it: distance, natural position, so many things to discuss. This is the problem with handball…There are reasons he can give the decision. It is always ‘soft facts’ with hands.”

That is precisely the issue with handball decisions on VAR. This was introduced to provide extra evidence to overturn “clear and obvious errors” in “match-changing situations”. The idea was that the VAR replays would be easy to judge, because they would only be used to establish the facts in a narrow set of circumstances. The evidence would be clear and the judgements would be objective.

But it has not worked out like that. When it comes to handball decisions, incidents are being re-refereed under the intense scrutiny of VAR. And it feels as if rather than the details simply being established, as VAR intended, they are instead being subjected to a different standard of what ‘deliberate handball’ actually means.

Deliberate handball has always stood out among the laws of football, the one area where subjective interpretation is required. That has never been satisfactory, and that is why IFAB are currently looking to change the laws in future. They want to remove the references to intent for attacking players, to mean that a goal scored accidentally by a handball would be disallowed. That could help to move handball from subjective to objective criteria, and when IFAB head David Elleray spoke recently about introducing references to a player’s “natural silhouette” to determine the offence, it felt like the start of a new definition.

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Getty Images The story of United’s win in Paris PSG 0-0 Manchester United PARIS, FRANCE - MARCH 06: Romelu Lukaku of Manchester United goes past Gianluigi Buffon of PSG to score his sides first goal during the UEFA Champions League Round of 16 Second Leg match between Paris Saint-Germain and Manchester United at Parc des Princes on March 06, 2019 in Paris, . (Photo by Shaun Botterill/Getty Images) Shaun Botterill Getty Images The story of United’s win in Paris PSG 0-0 Manchester United ... before finishing from a tight angle Getty Images The story of United’s win in Paris PSG 0-1 Manchester United PARIS, FRANCE - MARCH 06: Romelu Lukaku of Manchester United celebrates after scoring his sides first goal during the UEFA Champions League Round of 16 Second Leg match between Paris Saint-Germain and Manchester United at Parc des Princes on March 06, 2019 in Paris, . 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(Photo by Shaun Botterill/Getty Images) Shaun Botterill Getty Images The story of United’s win in Paris PSG 1-2 Manchester United Marcus Rashford shoots wide REUTERS The story of United’s win in Paris PSG 1-2 Manchester United Kylian Mbappe goes close but can't divert the ball past David de Gea Getty Images The story of United’s win in Paris PSG 1-2 Manchester United Chris Smalling snuffs out Mbappe in the box Getty Images The story of United’s win in Paris PSG 1-2 Manchester United Rashford is monitored by Thilo Kehrer AFP/Getty Images The story of United’s win in Paris PSG 1-2 Manchester United Angel di Maria gets in behind and finishes with a brilliant chip REUTERS The story of United’s win in Paris PSG 1-2 Manchester United But the winger sees it ruled out for offside AP The story of United’s win in Paris PSG 1-2 Manchester United Tempers flare between Ashley Young and Marquinhos AFP/Getty Images The story of United’s win in Paris PSG 1-2 Manchester United In added time, Presnel Kimpembe blocks a Diogo Dalot shot with his arm AFP/Getty Images The story of United’s win in Paris PSG 1-2 Manchester United The moment seems innocuous, but the referee Damir Skomina is told by VAR to check the replay REUTERS The story of United’s win in Paris PSG 1-2 Manchester United After a long delay for his deliberations, Skomina awards a penalty to the shock of PSG players Action Images via Reuters The story of United’s win in Paris PSG 1-2 Manchester United Soccer Football - Champions League - Round of 16 Second Leg - Paris St Germain v Manchester United - Parc des Princes, Paris, France - March 6, 2019 Referee Damir Skomina awards a penalty to Manchester United after a VAR review REUTERS/Benoit Tessier BENOIT TESSIER REUTERS The story of United’s win in Paris PSG 1-2 Manchester United Marcus Rashford steps up in the 94th minute... Action Images via Reuters The story of United’s win in Paris PSG 1-3 Manchester United ManU's Marcus Rashford scores his side's third goal from the penalty spot during the Champions League round of 16, second leg soccer match between Paris Saint Germain and Manchester United at the Parc des Princes stadium in Paris, France, Wednesday, March. 6, 2019. (AP Photo/Francois Mori) Francois Mori AP The story of United’s win in Paris PSG 1-3 Manchester United ... and fires confidently past Buffon REUTERS The story of United’s win in Paris PSG 1-3 Manchester United PARIS, FRANCE - MARCH 06: Marcus Rashford of Manchester United celebrates after scoring his sides third goal with teammates during the UEFA Champions League Round of 16 Second Leg match between Paris Saint-Germain and Manchester United at Parc des Princes on March 06, 2019 in Paris, . 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(Photo by Julian Finney/Getty Images) Julian Finney Getty Images The story of United’s win in Paris PSG 1-3 Manchester United A distraught Kimpembe at full-time REUTERS The story of United’s win in Paris PSG 1-3 Manchester United Paris Saint-Germain's Uruguayan forward Edinson Cavani (R) Paris Saint-Germain's Belgian defender Thomas Meunier (D) try to cheer up Paris Saint-Germain's French defender Presnel Kimpembe at the end of UEFA Champions League round of 16 second-leg football match between Paris Saint-Germain (PSG) and Manchester United at the Parc des Princes stadium in Paris on March 6, 2019. (Photo by FRANCK FIFE / AFP)FRANCK FIFE/AFP/Getty Images FRANCK FIFE AFP/Getty Images The story of United’s win in Paris PSG 1-3 Manchester United Soccer Football - Champions League - Round of 16 Second Leg - Paris St Germain v Manchester United - Parc des Princes, Paris, France - March 6, 2019 Manchester United's David de Gea and team mates celebrate as Paris St Germain's Edinson Cavani and Marco Verratti look dejected after the match REUTERS/Benoit Tessier BENOIT TESSIER REUTERS The story of United’s win in Paris PSG 1-3 Manchester United Soccer Football - Champions League - Round of 16 Second Leg - Paris St Germain v Manchester United - Parc des Princes, Paris, France - March 6, 2019 Paris St Germain's Kylian Mbappe looks dejected after the match REUTERS/Christian Hartmann CHRISTIAN HARTMANN REUTERS The story of United’s win in Paris PSG 1-3 Manchester United Rashford commiserates Mbappe AFP/Getty Images The story of United’s win in Paris PSG 1-3 Manchester United Soccer Football - Champions League - Round of 16 Second Leg - Paris St Germain v Manchester United - Parc des Princes, Paris, France - March 6, 2019 Manchester United interim manager Ole Gunnar Solskjaer celebrates after the match Action Images via Reuters/John Sibley JOHN SIBLEY Action Images via Reuters The story of United’s win in Paris PSG 1-3 Manchester United Paul Pogba, suspended for the match in Paris, celebrates on the pitch PA The story of United’s win in Paris PSG 1-3 Manchester United PARIS, FRANCE - MARCH 06: Luke Shaw, Chris Smalling ad Mason Greenwood of Manchester United celebrates at the final whistle during the UEFA Champions League Round of 16 Second Leg match between Paris Saint-Germain and Manchester United at Parc des Princes on March 06, 2019 in Paris, . 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But for now deliberate handball is still a grey area, subject to interpretation. Or what Tuchel called the “soft facts”.

And UEFA even knew this would be a problem when they decided that VAR would oversee handball decisions in the Champions League this season. UEFA chief refereeing official Roberto Rosetti tried to set the standard when he discussed the issue in January. He said that VAR must intervene when there is “clear evidence of a deliberate act of a player making contact with the ball with the hand or arm”.

Of course a “deliberate act” is open to interpretation, and Rosetti did separately clarify that the key to making the call would be the position of the defender’s arm. “It is not easy to see [if it is deliberate] because I can’t say I have ever seen a defender deliberately doing a handball,” Rosetti said. “The big challenge is the position of the arm. When the arm is totally out of the body above the shoulder it should be penalised. If the defender is making the body bigger in order to block the ball it is not fair.”

The VAR decision to award Manchester United a late penalty has sparked a debate about using the technology to decide penalties (Getty)

This is an objective standard, and if it was followed by all referees and VAR officials then it would mark an improvement on the current situation. Because the evidence of the last few weeks is that too many situations where a shot hits a player’s arm in the box is given as a penalty, completely out of kilter with fans’ and players’ understanding of the game. Even if the arm is not “totally out of the body above the shoulder”. Or when the defender is not “making the body bigger”, as per Rosetti’s own criteria.

The Kimpembe handball was only the most recent example of this. Two weeks ago Nicolas Otamendi was penalised, again by VAR, turning away from a shot in the box when Manchester City travelled to Schalke. It is an increasingly common situation in Italy too. Just last week Juventus’ Alex Sandro gave away a VAR penalty when Napoli’s Fabian Ruiz volleyed the ball into him when Sandro had his back turned. No one thought it was a penalty, except for the VAR officials.

Perhaps the first incident of this was at the World Cup final last June when the ball hit Ivan Perisic’s hand in the box, the type of incident that routinely happens in games but comes to nothing. But the referee went to re-examine it and after repeat viewings he convinced himself there was a foul. Even though, again, it did not feel like an offence in real time. France scored the penalty and went 2-1 up.

Clearly when so many referees make the same mistake, the fault can no longer belong to them as individuals. But when referees are being even harsher than the UEFA guidance, that suggests it is not even an issue of technical wording. But a problem with the technology itself. Even though the VAR guidelines say that slow-motion should only be used to determine contact with the arm, with full-speed replays to determine intent.

Football is a fast-moving fluid game, combative and physically draining. In the frantic rush of a busy penalty area, sometimes the ball will hit an arm, hand or elbow, even when no-one intended it to. But when that particular collision is isolated, taken out of its context, slowed down and replayed over and over and over again, it will look different. As if the arm’s position was unnatural on purpose. As if the handball was deliberate all along. There is now an inevitability now when referees consult the VAR screen, because the contact is so obvious, even if the intent is not.