It's a tough situation that we are not going to solve on this message board. Obviously, if people are guilty of domestic violence, you want to punish them, but if there is not enough to punish them criminally, do we want the default to be punishing them economically. Maybe we do, but the downside is that if victims know that their husbands will be fired regardless of what actually happened if they call the police, they are certainly going to be less likely to call the police to escape an escalating situation.
This case is not necessarily typical, because they are not married and there are no mutual kids (so it's not clear whether she would be harmed if he is fired and has trouble getting a similar job), but if we make the default that whenever someone calls the police, all of them suffer financially, you will end up with fewer calls to the police, even if the police could help alleviate the situation.