I figured I'd respond since whiteciv88 hasn't responded in a while. I know him personally. He did in fact have an alarm. However, he lives on a main road and trucks traveling by were setting off his alarm even when the shock sensor was on the lowest setting. He explained to me that he had just had the setting turned off.
I'm not sure why the alarm didn't go off when the car door was opened while it was armed though.
He also had a fuel cut-off switch. Unfortunately, he usually didn't flip the switch in his driveway because his other family members almost always parked behind him. Well, as fate would have it, nobody parked behind him that night.
Hopefully I cleared up a few questions.