Vingegaard nearly crashed out of a corner in the last part, which tells me he was not holding back when he lost that TT to Van Aert. If he was holding back, then he very likely would have crashed in that corner and would not have won the race regardless.He was also on his way to the victory of the longest ITT in the Tour of the past decade before he gifted it to Van Aert. This year is the only bad ITT he has ever ridden in the Tour.
By the same token, the MTT also showed that Evenepoel is quite inconsistent in ITTs.
Vingegaard has done subpar TT's other than the one this TDF. Only talking about the TDF TT's is cherry picking if you want to compare that to Evenepoel's consistency, who's previous bad TT (not top 10) was when he was sick and quit the race a day after.
If Vingegaard can stay within 30-40s of Evenepoel on a 50k flat TT, he should start doing the WCC TT as he would be on the podium. In a GT a lot also depends on when the TT is being held. Early first week, day 20... Even sprinters can do good flat TT's up to 10km. Doesn't mean you can extrapolate that to 20km, or 50, or 70...