A piece of advice.Do not let this friend drive your car again. He has no respect for your car or you.
One time? No, not even close. It's just fine.
After multiple times? Yes, surely something will happen.
Just leave this matter as it is.
I have question about car transmission, my car was on, and my friend rev the engine and then pressed brake switched to reverse when he let go of the brake it made a slight push because it was still high on rev, just alittle push, it's automatic did I do any damage? It's ford mustang 97 automatic, he let rev lower but not enough time just a slight push when he switched to reverse, I switched the fluid at a shop siad no pieces of metal what's so ever the fluid was change in time guy siad everything looks alright, still did I do damage? Car runs fine still