How is HE going to avoid punishment?
Well, one easy answer is that the "documentary" wasn't really meant to be aired in the first place - it was all just "home video" all along (this assumption may also be supported by the fact (or not?) that he was holding a camera before attacking Shelly - surely THAT episode was not for air...) However, if we don't stick to easy answers...
If the documentary goes on air, we can be sure the authorities will investigate into Shelly's most timely disappearance. Yes, the very final scene tells us clearly that chronology provided in the film is NOT reliable. So we may conclude that Leigh has prepared an alibi for April 1 (Fools' Day - is it a hidden clue, by the way?) when, according to footage, Shelly went missing. Still, the caption for that day says that not even the authorities knew about what Shelly was doing at the time. So there is little chance that the true murderer would be aware that Shelly posed a threat to him - except if that murderer was... David Leigh himself. Well maybe he's not the only one, but definitely his name would appear on the list. And if only he comes under suspicion - his movie would certainly be scrutinized to the smallest details, and even if no direct evidence of his manipulations is found, the very fact that the documentary was undoubtedly heavily edited by Leigh would be enough for police not to take it all at face value. And then David is in a HUGE trouble - even if the police never find Shelly's body (hint for 'em: look at the backseat of Leigh's car during "the reenactment trip"), they might just reopen Pine Barrens case.
Or... IS HE GONNA COMMIT SUICIDE? (To continue the chain of never-explained mysterious deaths with found footage...hence the title?)
Yet another question is - how did blood of the victims get on Suerd's shirt?
And again, the most simple explanation is that Leigh for some reason (haha) failed to mention that he was acquinted with Suerd and thus managed to set him up. However, I think that it's much more possible that Suerd actually found the bodies and touched them before he called 911. His trembling voice as can be heard on the taping of his call to emergency testifies to this as well, in my opinion.
