Continuity mistake: We see Vic outside the halfway house, just starting to chop a 4-foot log with a double-bit axe. In the same scene a few moments later, as Joey approaches, Vic has chopped about a third of the way through the log. Problem is, it's a completely different log (different shape, texture and color).
Revealing mistake: When Pete gets his throat slashed, you can plainly see that there's no actual cut, it's just a line of stage blood. (00:26:30)
Revealing mistake: Right after he gets off the tractor, Reggie's clothes appear to be dry, but he was out in the rain.
Continuity mistake: After Reggie's grandfather flies through the window, his head changes positions between shots. We can also see that he is breathing, even though he is dead. (01:10:10)
Revealing mistake: Violet has blood on the right side of her shirt before she gets stabbed. (01:05:10)
Visible crew/equipment: In the film the ambulance is called to Pinehurst. When the ambulance comes to a stop the boom mike can be seen in the bottom part of the rear window. (00:21:05)
Audio problem: When Junior is riding his motorbike around, screaming "they hurt me, ma," in many wideshots we hear him yell but his mouth is closed. (00:55:20)
Continuity mistake: When Robin and Violet hang up the laundry, the distance between the pink towel and boxer shorts increases between shots. (00:18:15)
Audio problem: When everyone is running after the police car, we hear Robin shout "Hey guys! Joey, c'mon!" but her mouth is shut. (00:14:05)
Plot hole: After Roy is knocked out of the barn doors, Pam and Reggie slowly walk over to look, but then Roy jumps up and grabs onto the barn floor. However when we see a wideshot of him dangling, you can see there are no ledges for him to have gripped onto while he fell, and that it's just a flat wall. Therefore he couldn't have popped up because there weren't any ledges for him to have grabbed a hold of on the wall. He should have instantly fallen on the tractor harrows. (01:18:45)
Continuity mistake: At the beginning of the film, we see boots walking through the woods. In a closeup they stop, and to the left boot there's a cluster of leafless branches. In the following shot from behind, they are gone. (00:00:50)
Continuity mistake: In the film Joey has chocolate on his face/left side of his mouth. The amount of chocolate changes on his left side as he is walking off the porch towards Violet. (00:18:00)
Continuity mistake: In the film Tommy tosses the alien mask that he wore to scare Reggie on his bed and the mask slides down the wall and is all crinkled up. In the following shots Tommy takes out another mask and you can see the alien mask now laying flat on his bed and away from the wall. (00:13:10)
Continuity mistake: In the film the killer.aka."not the real Jason" is seen walking through the rain soaked grounds and woods , but yet when he climbs up the ladder at the end of the film his shoes are pretty clean. (01:10:30)
Continuity mistake: When young Tommy is looking at Jason's grave the amount of leaves on the grave change between the shots. (00:01:20)
Plot hole: When Robin goes to bed you can see that Jake is not there. When she turns over Roy couldn't possibly have put Jake there in that short time without her noticing, not to mention that she was still awake. (01:03:30)
Continuity mistake: Jason stabs the machete vertically into the man's stomach, but when he pulls it out the machete is in horizontally. (00:03:30)
Continuity mistake: After watching "A Place in the Sun," Robin goes to her room and removes her blue gown. Then she walks to her mirror, and in the reflection we see the white door at the end of her bed is wide open. In the following shot into her mirror, the door is shut. (01:02:20)
Other mistake: After Raymond gets stabbed by Roy and falls dead, there is no blood visible on his body.
Revealing mistake: During several of the deaths committed by the impostor, look closely. The shirt sleeves are dark green instead of the dark blue sleeves of the jumpsuit the impostor wears. Clearly Tom Morga, the hallucination of Jason, did these scenes instead of Dick Wieand, Roy Burns/impostor Jason.
Answer: Yes, originally Tommy was going to be the new Jason. But the makers decided to go in a different direction for part 6.