Board Thread:Voting/@comment-5475153-20150207230942/@comment-24709951-20150208060209

I agree with Animaltamer7 on most points, excluding the "Lefty happened before the episode". It could be that the board showing a picture of Lefty is what inspired him the investigate the bowling alley in the first place.

Either way, the shorts seem entirely canon. The books have direct information about the show. I can't speak for the games as I haven't played them.