rear passenger door glass exploded while driving, is this defective glass or tempered glass problem ?
Tempered glass can explode at anytime.
Seen it many times.
Tester
The explosion could have been triggered by a small pebble or rock, something that you wouldn’t think should break a window, hitting the window that has some chip or defect as @Tester described.
Contact your insurer and ask what to do. They may cover it if your policy has a clause for it. If not, there may be a possibility for warranty coverage because it’s a side window.
I had this happen once at home. I heard a loud bang in the bathroom, went in, and saw a pile of glass pebbles on the floor. I never saw a crack and never damaged the door. I guess residual stresses from manufacturing eventually cause a smal crack inside the glass to fail catastrophically. Stuff happens.
Ask the dealer if it’s covered under warranty.