Continuity mistake: Immediately after Hourglass heads through the ceiling at the Comic Convention, several people are seen convulsing in the scattering crowd. This scene was appropriate only for the alternate ending, in which Hourglass does not go through the roof and tries to steal the lifeforce of those within the convention (the ones convulsing).
Continuity mistake: When Rick is walking down the street after the funeral, he passes a silver Pontiac Grand Prix, which is parked behind a Toyota. The same scene with a different angle shows another black car is suddenly parked behind the Grand Prix, without enough time having elapsed for the car to be parked there. Also, the Grand Prix is initially offcenter of the middle of the intersection, but the shot with the third car shows the Grand Prix in the center of the T intersection.