Audio problem: When the female TX is stopped by police during the intro credits, before the officer speaks you can see the TX's lips moving saying "Is there a problem officer" but her audio is muted. (00:08:50)
Audio problem: While the T-101 takes off the crowbar at the gas station it makes a clanging sound before it even leaves his hands. (00:43:15)
Audio problem: When Arnold makes the slow turn at the cemetery from Dr. Silberman's view, he starts firing his weapon at the police but we don't hear it. In the very next shot, he repeats the same action but we hear it this time.
Audio problem: When the T-X steals the car in the beginning, she's driving with both hands on the steering wheel. The car appears to be a 2001-2003 Lexus SC which has a 5-speed automatic transmission (without steering-mounted paddle shifters). However, the sound from the transmission indicates it's a manual transmission rather than an automatic transmission. Therefore, she cannot be shifting gears while having both hands on the steering wheel. (00:07:15)
Answer: He was originally in talks - and by some reports, did appear on set for some period of time. While factual answers are in short supply (for obvious reasons), there appears to be a connection to his drug-use habits. For instance, he was checked into a hospital (LA Cedars Sinai) for what friends feared was a drug overdose in April 2001, and has been in and out of rehab over the years. Chances are the production company was unable or unwilling to get completion insurance.
Rooster of Doom