Shark in sort of general area proves what?
A while ago, someone suggested a Pacific sleeper shark (a slow-moving but pretty awesome species, which may get to be 8 m long) as a candidate for the Lake Iliamna monster, more often presumed to be a tall tale or (as I think) a white sturgeon. In King Cove Lagoon, a brackish sea-connected lake hundreds of kilometers away, a sleeper shark having some trouble with hte shallow waters was videotaped. It's an interesting story, but claims it validates this fish's presence in Iliamna don't seem valid to me.
By the way - thanks to Thomas Cook for sending me some information on Lake Iliamna I had not seen before, including his own correspondence with scientists and officials.