Oh yeah... I'm guessing somebody, maybe "Chris Mitchell" started trying to erase the evidence. Or possibly, somebody somewhere realized the dude had violated copyright law and even though the school sanctioned showing the plagiarist's work in a public venue last December, he figured he better take it down now that everybody knows what a buffoon he is.
Seriously, based on the FB conversation, he's either a lying thief or a complete idiot. Either way... doesn't reflect well on BSu.