Does this still happen in Haunt 16 even if the traitor dies?
The house is still in danger of blowing up. The FAQ clarifies that the traitor still gets turns:


  A dead traitor can still move monsters, etc., during his turn.


If this weren't true, the heroes could usually pull off an easy win by killing the traitor and then taking their sweet time to scour the house for helpful items. This would be imbalanced, boring, and, as you mention, thematically inconsistent.