From: TropicMoon10 | #004 Forgive my ignorance, but does it matter? I'm pretty sure people are afraid Valve is going to find out which items are duped, and delete them all at once, so people trade Max heads sort of as a game of hot potato.
aka The Marvelous Breadfish http://steamcommunity.com/id/Sushimomioma
According to that, 41.2% of all max's heads are from a "timed drop". The thing is, they should all be steam purchase or traded. Max's heads aren't supposed to be a random drop. That's probably a side-effect of the dupe process.
It also looks like TC got rid of the hat already since it says "this item was traded or deleted".