I'd like to see if he came up with the other 25K chips he supposedly took as a souvenir of his wins before I say he's definitely a cheater but he's definitely a moron.
He would have had to take the TD or security directly from the casino, after telling them this story, to his house, not stopping to talk to or phone anybody, & show them those other chips he kept as souvenirs before I'd even entertain the story he told especially with the main event starting the next day.
Add to it that he removed the chip before he even won adds to the probability that this was done for nefarious reasons.
This looks bad for him & this probably happens a lot more often than we think.