In 92-99 and maybe earlier GM used two switches, one on the handle, one in the jamb. That way if someone walked up and pulled the handle on the locked car, the interior lit up. The mention of the bong not occurring when the handle was pulled w/o being opened gives it away.
For most of us with key fob'* it'* something we'd never miss. I press the button, the car lights up and unlocks at the same time.
This issue is one that typically happens to the drivers door because of the amount the handle is used. By unhooking the switch to that handle, the circuit is broken and most of us would never know that it'* unhooked or hooked up.