My question involves criminal law for the state of: Oklahoma

My daughter has a long history of violence and unruley behavior. I sent her to live with her dad after the 3rd time I had to call the police, and hold her down until they got there. She was on probation for throwing a knife at a girl.
Long story short... He ended up going through the same thing, except she hit him, threw things at him, and broke and destroyed things in the house. He never hit her back. She would rage and destroy everything in the house. The last time (now referred to as THE event) she hit him 3 times in the back of the head with a tennis racket, leaving him bleeding. He shoved her back so she couldn't hit him anymore and told her to get out of the house. She huffed out the door. after a few seconds to clear his head, he went to find her. She was a couple houses down the road, walking down the street. He got her by the arm and told her to come back home. She swung the other arm around, he dodged, so it was only a glancing blow to the eye. After that, he let her go, but kept trying to get her to come back home. He told her he was going to call the police again, and she snatched his phone, and threw it in the ditch. She kept jumping at him swinging, and he kept stiff arming her to keep her out of strike range. A man drove up and saw what he thought to be her dad pushing her to the ground, but it was her losing balance after running at him and receiving the stiff arm. The man said he was going to call the police, and her dad said, PLEASE DO! I NEED HELP! then a couple other ppl were standing around and my daughter fell to the ground and went from the raging agresser to the victim.
Fast fwd a few months, and she had moved back in with me. I had already had to call the police again, and had her evaluated at a psych facility, on the suggestion of her probation officer, and was diagnosed with oppositional defiance disorder. She was not in school, as she had already been kicked out of 2 and told me she was going to fight everyday until the new school did the same. She recalled the events differently than she had when the event occurred. She no longer claimed he hit her, and her story was pretty much the way he said it went down.
Cps did their investigation and determined there was no need for them to get involved.
Well, about 10 months after the event, her dad found out there was a warrant for him because of this.
The problem is, he was on probation for a dui at the time of the event (late Sept 2010). He completed his probation with no problems, and his probation officer cut him loose early. So when he found out about the warrant it was July 2011. He just happened to call the courthouse with an unrelated request for information.
Now he has the assault (that never happened) and a probation violation. He plead not guilty and requested a judge trial (his really crappy lawyer said this was better than a jury). He isnt too terribly worried about the assault, since she had already changed her story of the events. She wanted to go to the da and fill out a request to drop the charges, and included that she was never questioned by a cop, or give a statement of any kind. Also, the witnesses gave 2-3 sentences and were extremely vague. They also said her temperment and behavior and history don't come into account.
My question is, if this goes to trial and is dismissed, shouldn't the probation violation be dropped too? His attny said no, that even if someone lied to get charges pressed, there were charges filed which is a violation. How can that be true? Also, are you allowed to defend yourself against an attack from a minor? They are saying even if he didn't hit her, the stiff arm to block more attacks was assault.