I personally believe that this Doom3 leak has gotten way too much attention, I mean, this after all wasn't even an Alpha.
It was a "show off" or movie if you like of the Doom3 engine, nothing else!
This is a hoax. John never sent any memo out and if he had, no one here would be sharing it because they'd be out of a job so fast it wouldn't be funny. It's not like we have 500 employees and couldn't trace where something like that would come from. Anyone who has the barest clue of how this company works would know John wouldn't be the one handling an "investigation", nor would he be the one sending out a memo.