Why didn't the defence get an expert in to show how easy it is to change dates? Why not demonstrate copying the data to a new file and saving it, hence modifying the date? Or even re-saving it and having the software automatically change the modification date due to some hidden encoding or formatting setting?
Since when does a modification date count for anything!? There are countless reasons why it might not line up, both nefarious and perfectly innocent. And even if nefarious, it doesn't disprove the claims or invalidate the data, it only proves that the competition is rigged.
Which since they were created just before the competition, apparently wasn't possible.
Even if someone did all you said and accidentally changed the file modification date, you should have some original data source with an earlier file modification date.
The idea that someone would set up some kind of hacker convention and offer a reward for hundreds of experts to parse through random fake data that they intentionally created sounds beyond insane. It's just not believable. If that's where we're at, I might as well believe the majority of conspiracy theories which are less far-fetched than this one.