Former pro and high stakes player here. I don't know the principals involved and as such have no particular strong opinion on whether any cheating occurred, but this particular situation of a ridiculous hero call based on a very specific read is common enough that it doesn't raise any red flags to me.

Mostly I just want to comment to say that any analysis involving her hand equity against a random hand is flawed. For one, bluffs generally don't come out of a random range. Probably more importantly, someone deciding to have undue confidence in their read and acting on it is more common than some people here seem to think. It's pretty clearly a bad call under almost any reasonable analysis, but I wouldn't have been making a living if people made good decisions all the time. In this particular hand, if you convince yourself that the opponent has exactly 8c7c (not hard to do), it's also going to be pretty easy to convince yourself that a hand with the Jc in it is a good enough candidate to snap off that bluff.

Meta-considerations about offering to return money or the likelihood of choosing to burn an exploit for a very marginal situation don't seem particularly convincing one way or another unless you know the principals well. However, if I had to choose one word to describe a high stakes poker player, "erratic" would be a pretty good one. Basically I think anyone uninvolved who's sure of what happened is probably being overconfident.