Stephanie, I believe Clark's step-mom really does kill him. I'm not sure if it was in the explosion or not though. On the commentary for this one, Bruce Willis says he didn't get that Clark's step-mom killed him until then while they were doing the commentary.
This is confusing. I always thought the stepmother killed him in, that he really was in the car when it blew up. But D&M, the great detectives, figured out that he couldn´t be. Well, that didn´t help at all. I´m still very confused.
Okey, she must have killed her stepson before reporting the "second" kidnapping. That makes most sense.