Anyone who saw the videos of the crazy plays that he makes (or even just looked at the hand histories), including a situation where he goes all in over a 4bet in a situation where people are almost never 3bet bluffing. A situation where he calls all in preflop with 54 CORRECTLY against two AK.
Or my favorite,
the situation where a guy calls him down with pocket jacks because someone told him that Mike Postle is a possible cheater, on a board with two overcards.
I mean come on, anyone that is a poker player knows that only cheaters play like that.
The legal problems complicating this case is that most non-poker players don't understand how poker works. So of course a judge is not going to find it obvious, since there was a botched (some would say coverup) investigation done by Stones Gambling Hall, which would have faced possible legal and commercial repercussions for admitting that cheating was done in their establishment (on stream no less).
This was the path of least resistance for all parties involved, especially with law enforcement deciding not to get involved.
That doesn't change the fact that it's really obvious to anyone that has looked at the hand histories that Postle is a cheater. The details of that cheating may not be obvious, but the cheating itself is obvious.