Windshield cracked when the "car slipped slightly" off the lift. What kinds of other damaged could be done with such force?

A little flex in the body and a scratch or chip in the glass, doesn't take much to turn that into a crack. Your dealer is being fair with you.

Glass is far less flexible than steel/aluminum or rubber and other components of the car that are built to handle vibration on the road. If there is other damage, it should be readily noticeable in the handling of the car while on the road. The fact the dealer has informed your friend of the issue is a good sign. They would be liable for other problems if there is any other issue that would impact the safe operation of the car, so I would imagine they've inspected it while up on the rack.