Every ambulance journey is a risk for the crew and for other people who actually had accidents while someone intentionally messed themselves up.
I am chilled out in extremis, but that does not mean your pal is not a plonker.
Were his injuries assessed at the scene as needing airlift, that would again be another set of risks he imposed on other people.
He is a good rider, and I liked the intermix of trials machines, but when you are going to undertake serious stunt work you should think about nets, lines, etc.
Especially after you cocked it up a couple of times...