You talking about the side window on the body, not the door? That's glued to the body, and I would have a glass shop re-do it. Kind of surprised he was able to push it out. Anyway they'll likely cut it out, clean the channel, and re-install. Takes a urethane adhesive that is made for auto glass installation, and the surface has to be prepped properly. Bodies with glue-in glass (like the windshield) are designed such that the glass is part of the structural strength of the vehicle; in a rollover type crash they support the roof instead of just popping out. Improper installation or repair, they can pop out and not provide that extra protection.
Richard