Someone should be writing a fat check and/or going to jail over this. And it's not the frightened girl or her boyfriend, either.
It's their home. If you don't have a warrant and they won't let you in, Mr. Rambo'ed up Po-Po, you don't come in. Period. I don't care how much 5.11 gear you're wearing. Enforcing the Law is no excuse for ignoring it.