Continuity mistake: When Steven is fighting with Randy by the police car, you can clearly see in one shot that he has his gun in the back of his pants, but later he pulls the gun out of the front of his jeans. (01:03:15)
Continuity mistake: When Steven runs possessed Robert over, black blood covers all of the bottom of his shirt, and all his trousers. But later, when he comes to the police station they're clean. (01:01:10 - 01:06:00)
Continuity mistake: When Deborah returns back to the tent, it pans across to show the dead body of Alexis propped up against a tree. In a following shot from the point of view of Phil, who is possessed by Jason, watching the tent from beind some leaves, you can see they body of Alexis has now gone. (00:29:55)
Continuity mistake: The white sweater, tee-shirt etc., that Agent Marcus throws in a heap beside the sink change position from when she runs the bath, to when the lights go out. (00:03:45)
Continuity mistake: Dirt and grass disappears from the back of steven's sweater, just before Jason throws him. (01:20:10)
Continuity mistake: When Jessica stabs Jason, black blood squirts over his hockey mask, but in the next shot it has gone. (01:20:25)
Continuity mistake: The blood vanishes from the pole which goes through Duke's leg. (01:14:55)
Continuity mistake: When Jessica arrives at the Voorhees house, her neck is clean, but when she enters the room with Duke in it, she has a black handprint on the side of her neck. (01:11:30)
Revealing mistake: At the end of the film when Freddy's arm bursts out of the ground and grabs Jason's hockey mask, you can see none of his skin is burnt, like it should be, and also they metal blades on his glove clearly bend like plastic. (01:23:50)
Revealing mistake: After Steven cuts possessed Randy's throat with a machete, you can see that the machete is completely free of blood. (01:15:55)
Visible crew/equipment: When Pookie shoots at Robert, who is possessed as Jason, in one side shot you can see Pookie is wearing safety goggles. In all the other shots he has nothing around his eyes. (01:09:00)
Continuity mistake: When Steven jumps upwards, and out of his handcuffs, he knocks out the policeman who was walking with him. As the policeman falls to the floor, his hat falls off. However in the next shot the unconscious policeman is lying on the floor with his hat back on his head. (01:05:20)
Continuity mistake: When Vicki is cleaning the bloodstain from the carpet, Jessica enters the room and they talk. Between shots the yellow rubber gloves and the small sponges which sit on the bloodstained carpet change position. (00:41:30)
Continuity mistake: When Josh attacks Diana, Steven tries to save her. We see Steven being taken by the police and his blue jeans are spotless. Yet in the very next scene of Steven talking with Randy at the station, Steven's jeans are now soaked in blood, for no apparent reason. (00:40:35)
Continuity mistake: When Josh is impaled by the poker, he stumbles towards the window and crashes out of it, pulling the white curtains with him so that they drape outside the window. But in the next shot the curtains are pulled back neatly inside the room once again. (00:39:30)
Continuity mistake: When Josh is attacking Steven, after Steven tried to save Diana from Josh, the small table with a lamp, photo frames and other ornaments on it has half it's items knocked off, with a couple of ornaments remaining on it. In the next shot, these ornaments have also gone. In addition, the green rocking chair next to the table, has a decorative cloth sitting on the seat of the chair, but in the next shot the cloth is draped over the back of the rocking chair. (00:38:45)
Revealing mistake: Phil, who is possessed by Jason, puts shaving cream on Josh's moustache. Then, he takes a razor and begins to shave his stubble off, and then his moustache - however, you can quite clearly see that Josh's moustache is not there anyway, and has disappeared between shots. (00:36:00)
Continuity mistake: When Phil, who is possessed by Jason, has Josh tried up inside the Voorhees house, he takes some shaving cream and puts it all over Josh's moustache. However in the next shot there is suddenly much more cream on Josh's moustache/chin. (00:35:45)
Continuity mistake: When Diana walks out of the doors carrying a silver tray, you can see inside the tray and it is completely empty. However in the following shots as she walks across the car park, there is now a white bowl of dog food inside the previously empty tray. (00:32:20)
Continuity mistake: When Alexis is outside by the campfire, she is fiddling about with a blue sleeping bag, which is rolled up in a bundled circle. However in the next shot the sleeping bag is suddenly rolled out flat across the ground, and Alexis now unzips it. (00:26:55)
Answer: There isn't much of a feasible in-movie explanation. In truth, the entire scene was added by the director because he felt the movies were pretty sexist in that it was mostly women who were either nude or sexualized. Thus, he added an inherently homo-erotic sequence involving one man shaving another stripped man to "level the playing field" so-to-speak. The only real explanation I could think of is that maybe the creature just thought it'd feel uncomfortable transferring to a man with a mustache. But even that's shaky at best.
TedStixon