First of all, which agency responded to this incident? Based on the limited amount of information, it sounded as if this may have occurred inside one of the municipalities. Most municipalities have what basically is a rubber stamp court, where most everyone is found guilty, fines imposed with very limited if any investigation of the incident by a law enforcement agency.
I also find it odd, that they allowed a counter charge of harassment, prior to the first case being disposed of, unless there was documentation available which provoked the actions of the ex-wife.
If the information you posted is correct, I would appeal the case to the Circuit Court of the county in which it occurred. I do not know of any jury that would convict anyone of defending themselves, especially in their own home or property.
Another question which I have is, if the ex-wife entered your friend’s home without permission, and assaulted your friend, why wasn’t the ex charged with burglary? During a recent grand jury we discussed the elements of the crime of burglary and if my memory serves me correctly, the information you provided would meet that criteria.