When Hiro replaces the film in the trash can, he puts it down into the trash can just like Mohinder had it. When Samuel comes into the room, the film is at the top of the trash can with half of it sticking out above the can.
When Mohinder is shown watching his father's movie regarding Samuel's birth he watches film being projected from a "reel-to-reel" cine projector. Whilst the front reel of film turns, the rear 'wheel' does not turn, however, thus meaning the film would be being spooled to the floor and not onto a new reel and there appears to be no drive to the front reel so the film should not play. In some shots over Mohinder's shoulder, the rear reel does turn.
In addition, at certain points, the front reel turns at an inconsistent speed which would not be conducive to watching a traditional negative-image type film in any watchable, regular, format.
Rene the Haitian has the power to block other Heroes from using their abilities. Yet when he is standing near Sylar (shape-shifted into Nathan) Sylar remains in Nathan's form. No explanation is offered as to why Sylar's ability still functions.