depends whether its gone past the clearcoat as its hard to tell from that picture.
As above. If he hasn't gone through to the paint/primer there is a chance of getting it out. Know anyone who works for a bodyshop who could perform some paint rectification tricks on it?
If he has gone through it then you'll probably be looking at a spray or a proper touch up session.


Mind you, as long as he doesn't do it to anyone else's motor... 
