As any good farmer will tell you, always shut the gate. On Thursday a number of government MPs, including several ministers, rushed away from parliament, leaving the gate wide open, and the opposition surged through, taking charge of the big paddock.

Malcolm Turnbull’s fury is boundless. He is not a man to hide his emotions.

In a massive Friday morning spray on Melbourne’s 3AW, he declared of the offenders, among them Peter Dutton, Christian Porter and Michael Keenan: “They did the wrong thing, they know they did the wrong thing. I’ve read the riot act to them. Their colleagues will all read the riot act to them, they’ll get the riot act read to them more often than just about anyone could imagine.

"Two of them were cabinet ministers and one of them was a minister. They’re grown-ups, they’re experienced parliamentarians. They knew that they should not have left and they left early because they thought they’d get away with it. They’ve been caught out, they’ve been embarrassed, they’ve been humiliated, they’ve been excoriated. It won’t happen again.”

He’s right of course – they do know better. They just believed the rules were there for others. But one does wonder at the strength of Turnbull’s language in his public dressing-down of very senior colleagues. Maybe it could have been pulled back a fraction, given the individuals already felt like crawling under rocks. But that’s Malcolm. Always lets it all hang out.

Apart from the excoriating of the guilty, questions are being asked about Christopher Pyne, who as leader of the House of Representatives should have had his party’s house in better order. To say nothing of the whips, feeling the lash themselves.

Objectively, for the government to lose some procedural votes as the opposition tried to bring back its push for a royal commission into banking is not a disaster. The numbers were retrieved in time to prevent Labor getting a substantive win, although it came close.

But in the battle of tactics, psychology and public perceptions, it was appalling. Labor delights in saying this is the first time a majority government has lost a vote since the early 1960s, when the Menzies government also had a tiny margin.

Labor was taunting Turnbull over his claim to have a “working majority” – which he does, of course, but only if his MPs are all present, ready to vote. To have lost control, even briefly, of the House where governments are made and can be broken is alarming for a prime minister. Especially coming on top of events earlier in the week, when Coalition senators defied Turnbull over the Racial Discrimination Act, showing he was not really in charge of his party.

Thursday’s affair resulted from a lack of the most basic discipline. It created the impression of an untidy, flat-footed government up against an agile opposition, with the public takeout being that the government was shambolic. It ensured Labor ended the clear winner of the new parliament’s first week. Without the stuff-up the assessment might have been closer to a draw, given the ALP’s problems with Sam Dastyari’s Chinese connections.

Those in the government trying to find any bright side say the obvious – nobody will ever lapse again. A “wake-up call”, Turnbull called it. The sort that leaves you trembling in a cold sweat.

Having to front the Liberal federal executive, which happened to be meeting on Friday, amid such embarrassment probably added to Turnbull’s angst. The executive signed off on former trade minister Andrew Robb leading the election post-mortem. If the report is honest, it won’t be flattering of Turnbull.

This inaugural parliament week has reinforced the point that Bill Shorten plans to do everything possible to harass Turnbull; he’s also following the Tony Abbott example of riding on totemic issues. With Abbott it was scrapping the carbon and mining taxes, stopping the boats. With Shorten it is agitating for a banking royal commission, and protecting Medicare, both hot buttons electorally.

As Shorten relentlessly pursues simple messages, Labor is resorting to elaborately planned tactics. Thursday’s ambush involved having someone at the airport to watch out for the arrival of Coalition MPs.

While Shorten has to be careful not to appear excessively obstructionist, so far his approach is working a treat. This week’s Newspoll, the first since the election, had a 50-50 two-party vote and Turnbull on a net approval of minus 18, compared with Shorten’s minus 14.

Turnbull now has a week overseas, departing on Saturday for the G20 and other engagements of the “summit season”. That leaves Deputy Prime Minister Barnaby Joyce in charge at home, always a situation with potential. Like some of his colleagues, Joyce too had left the building late Thursday. He missed an early vote which the government won, but fortunately got back in time for those it lost.