Audio problem: When Myles is at the party in the office checking out the web broadcast, a guy and a girl bust in and intend to have sex there. What we hear the guy say doesn't match up with his mouth movements.
Audio problem: When Donna runs into Michael in the sewer, she screams, but we hear the words, "Oh, shit."
Audio problem: Take note of when Michael Myers brandishes his knife. Any time the knife is shown, an audible, metallic 'SHHHING!' is heard, as though the weapon is being pulled out of a sheath or scabbard. Even when the knife is being held still, the sound effect is still heard. It gets to the point of being almost comical.
Audio problem: When Harold is talking about Michael's past, his lips are not moving as he says that Michael killed three nurses and a paramedic.
Audio problem: When Freddy is watching Fist Of Fury he hears the doorbell and says something as he turns his head, but his mouth doesn't move.
Audio problem: After Michael is hung by the camera cord Sara receives a message from her palm pilot saying, 'HE'S STILL ALIVE'. The palm pilot beeped before she got the message. (01:11:10)
Audio problem: At the start, Sara is driving her moped at the school. Jen arrives and asks, 'Guess what?' Then she says, 'We gotta find Rudy. Come on.' When she says 'Come on,' her mouth doesn't move. (00:17:20)
Audio problem: After Donna is killed you can hear her still screaming.
Audio problem: When Sara enters the large room with the meeting with Freddy, Jen comes up to her and says 'Sara,' but her mouth doesn't move. (00:20:55)
Audio problem: At the very end of the film Sara wants the fireman to open the bodybag with Michael Myers in it. When he does Freddy says,'Uh oh.', and as he says this the words do not match up with his mouth movements. (01:20:25)
Answer: At first impression, Laurie was catatonic not only from the shock of killing an innocent man, but also from a lifetime of being chased down by her murderous brother. She obviously knows from past experiences that nothing she does (including faking her own death) will stop Michael from finding her. It is later revealed she has been faking her mental issues (think when she has been hiding her regular meds in the raggedy Ann doll) and is committed only to stopping Michael, no matter what the cost. She may have also been trying to protect her son and the only way to do that is to allow herself to be institutionalized in order to lure Michael there.