Audio problem: Sean drops frozen Jenna and she shatters. He then manages to casually walk out of the room over her without crunching any of the ice. (00:17:30)
Audio problem: When Sean flags down Whitney's truck, we hear his brakes squeal as he slams on the pedal. A few quick cuts later we see him do the same thing, apparently for the first time. (00:33:25)
Audio problem: While Sean and Whitney are tossing the football at the lake edge, at one point we hear Whitney catch the ball offscreen while the camera is on Sean. The camera then cuts back to Whitney and he catches the ball on screen. (00:03:20)
Answer: No, there is no such character in the comics. He's a "meteor-freak" like all the other baddies on the show. The sound has something to do with him vibrating his vocal cords very fast to create a high-pitched squeal.