If the other guy made a claim, your friend will get a letter in the mail, usually within 10 days. after getting the letter, your friend has 5 days to call ICBC.
So yes, he should have been contacted already, again, by mail.
Depending on the other car. If the other guy goes to ICBC and they see that his bumper was fucked to begin with, they will cite previous damage and probably not award him much.
A cheap prep + paint costs about 4~500. ICBC has a book with values, so the other guy can't gouge your friend.
It probably wasn't worth the other guy's time. I know if I was driving a 20 year old beater, I wouldn't want a brand-new rear bumper to go along with the faded and rusty rest of the car.