I think I've said this before, but several years ago someone posted on our local FB chat something about a red van, with a broken back light, that had tried to pick their dc up and had driven off recklessly.
Several people commented along the lines of "OMG! I saw that van. It was driving really badly, nearly hit the car in front..." Tbh if it had genuinely been seen in all the places people claimed then it definitely would have been driven recklessly.
A couple of hours later the original poster came back and apologised. Turned out the driver of the van had stopped and pointed out their dc had dropped something from his bag. Dc had expanded this in his mind to being talked to by a stranger in a van and panicked. Also turned out that the van was visiting one of their neighbours and had pulled into their drive, and not gone out again within a couple of hundred yards of speaking to the dc.
This was within a couple of hours of the event. These people were totally convinced they had seen the van, and that it was driven badly.
It's confirmation bias. You hear about it and your memory corrects what you actually saw to equate it with what you saw. You're very convincing because as far as you are concerned, that is correct, you're not lying. But it isn't actually what happened.
It's perfectly normal in memory, even for recent events, let alone years ago at a traumatic time.