The requirement for a broken leg seems to be needed for anything to happen - well, serious contact anyway.
For me it is like having kids drive round an estate at 90 miles an hour. If the kill a kid, then they get a big sentence. If the don't, they get a trivial sentence. This is insane. The fact of doing the act is no different. Punishment should take place even if there was not a bad result (due to luck).