Bad mistakes? They made a few.

Dropping Joe Root (twice), taking two wickets off two no-balls, not reviewing a decision against Stuart Broad when England were seven-down in the first innings and he was on 4, dropping Jonny Bairstow in the second innings when the lead could have been clipped to under 300 - those are all the basic things South Africa got wrong and it cost them dearly.

They may have bowled England out for 200 runs fewer, they may have ended up with a competitive first-innings total, their comeback with the ball in the second dig may have put them in a match-winning position, and there may be life on Mars. We cannot hypothesise too much.

Sure, losing the toss was not ideal on a surface that turned square late on day four, but it is not the only reason South Africa were unable to put up a proper fight. Their batting has been brittle for some time but they have not needed to address the issues because they've always had someone or something to bail them out. In their last six Test innings, they've lost half the line-up before reaching 100 three times. Against New Zealand, they were 94 for 6 in Wellington before Temba Bavuma and Quinton de Kock put on a match-winning partnership, and 59 for 5 in Hamilton before it rained. Here, they were 94 for 9 and there was no-one to save them.

The top four have been the main concern, with an unsettled opening pair and out-of-form experienced players at No.3 and 4, for whom there has seemingly been no suitable replacement. Naturally, that's put pressure on the middle-order, which South Africa have packed with potential but are smothering with stress. Bavuma and de Kock cannot dig their seniors out of every hole; Vernon Philander and the tail should not have to. So what are South Africa to do?

In this series, they experimented with a fourth opening partner for Dean Elgar, after Alviro Petersen, Stiaan van Zyl and Stephen Cook, and with good reason. Since the start of 2015, South Africa's opening pair has a better average than only West Indies, Zimbabwe and Sri Lanka, so theoretically, it is a good idea to keep trying to find the right combination - and Heino Kuhn deserved his chance. He has been a stalwart of the first-class scene for more than a decade and, last summer, became one of only four players since the start of the franchise era to score more than 1,000 runs in a season. He topped that up with a double-hundred and a century for the A side, so overlooking him did not seem like an option.

Hashim Amla received a nasty delivery from James Anderson Getty Images

But to play Devil's advocate for a bit: if the selectors decided it was time to invest in a solution, they could have looked for someone who would be a longer-term answer so that, if he struggled early on, they would have been able to give him a longish run. Aiden Markram, the Under-19 World Cup winner, is also an opener who has done well domestically, was included in the Test squad as cover, and could have been blooded. Now, Markram will return home to play for the A team, so Kuhn will have to be able to help Elgar stabilise things at the top. End of.

Kuhn's record suggests he will come good at some stage but South Africa don't have the luxury of time. And, in the back of their minds, they may even wonder whether they should have bypassed him completely, harsh though that may have been.

Then there is the question of Hashim Amla and JP Duminy and what South Africa need to do to get them firing. Amla has been struggling since the Australia tour last November and, even though he scored a century in his 100th Test against Sri Lanka, something is ailing him. It's too easy to lean on the "class is permanent" cliche as a way to escape the uncomfortable truth that he may be on the wane, but South Africa may have to because Duminy is the bigger problem. If someone has to take the fall for this defeat, it has to be Duminy.

For too long, he has kept his place based on occasional past performances that provide a reminder of how much he has to offer. But those occasions have become too scarce and Duminy has less to bring to the table than Amla. He does not inspire any confidence at all, in everything from his presence to his strokeplay. What a coincidence, then, that the only shot he played in anger was a full-blooded pull to midwicket on the stroke of tea that confirmed South Africa's slide to a four-day defeat.

There seems to be some turning of the tide on Duminy, especially with Theunis de Bruyn showing good signs in this first-innings 48 and so the solution on this tour might be to drop Duminy, have returning captain Faf du Plessis at No.4, Bavuma at No.5 and de Bruyn at No.6. That still means leaving Quinton de Kock at No.7 for now, but that may be the best South Africa can do.

De Kock's aggressive batting style and quick accumulation of runs makes him an obvious candidate for higher up, but the hours he spends keeping wicket and the impact that will have on his long-term workload have to be borne in mind. It may actually work in South Africa's favor to have him lower down, facing the second new ball and marshalling the lower middle-order, provided the top four can come good. All South African supporters want to see de Kock given the opportunity to do more, but they would not want him to be burdened by the expectation that will come with that. We've already seen what undue pressure does to South Africa; at least one star player should be allowed to continue with freedom.

South Africa have had their share of sand kicked in their face in this Test, and they have not come out of the experience well. Not yet, anyway.