Neck Cranks can mess you up for a long time.
Like other submissions. I’d say they are on the “more” dangerous side as opposed to a wrist-lock for example (which doesn’t mean a wrist-lock isn’t dangerous).
However the neck/spine is a sensitive area and if a person is ignorant of this technique they may wind up getting seriously injured.
A few months ago I was sparring with a person and was unaware neck cranks were legal at their school. So as I went to pass (over/under) style I was caught in like a half-nelson crank. It was painful and I was hurting for a few days afterwards.
My fault, I should have known the rules and tapped earlier rather than acting surprised.
Overall, besides having to ice it for a week it was good to learn about it and understand it.
Now, I’m not sure about everyone else but if you were injured prior and unaware of the position it’s possible a person could have gotten seriously hurt because it can come on fast.
Which begs the question. Are neck cranks legal at your school and if so at what level?