If you change it to be in Canada, all he would have to do is give his insurance number. I'm not sure about the reporting or rules about contacting parents, but he could be seen without much delay as long as he knows his insurance #.
In the US, I don't think it's that easy. Once when I was a kid, my grandparents were taking care of me and I was really ill so they took me to the ER. The people in the ER wouldn't see me until they had confirmation from a parent that they were allowed to do so. I couldn't get in touch with my mom (who is my sole guardian), so I had to call my dad and then they gave me treatment. Although...if you do want to have something like that in your plot, you could have your character call someone who pretends to be a parent. In my situation, they did nothing to verify that the man on the other end of the line was really my father (and they didn't pay attention to the fact that he's not my legal guardian at all). So, that might be something.
hope that helped a little!