It's not really too much damage, but the door is dented in pretty good and probably needs to be replaced and painted. Probably going to cost at least $2000 or $3000 worth of damage.
I'll give the guy credit for not taking off. He actually went out of his was and told the valet guys what he did when he could have easily just left. No one saw it happen but him. I could have easily just come back to a car with a giant dent and cracked paint. Accidents happen, I guess.