Sounds like a lost time OSHA record able. That is why the boss didn't want you to go home! Lost time OSHA record ables can result in fines and normally brings OSHA representatives on location to review working environment and review the written working safety procedures and training programs.

It sucks to get hurt, but you also have to realize why employers/supervisors react the way they do sometimes.

In my line of work as a supervisor if too many OSHA record ables occur on my watch I can loose my job!

Technically he violated other OSHA laws by not having you recieve any medical attention or signing a waiver.