I worked for the Oregon courts for 5 years. You might be surprised at how little evidence is required for a restraining order. You might also be surprised at how little it takes to charge someone with domestic violence and how biased against men the justice system is in terms of DV cases. DV cases are very often instances of both parties being violent towards one another but only the man gets charged. I once saw a man charged with felony DV assault for cutting his drunk wife's hand when he yanked the keys away from her so she couldn't drive.

I don't disagree with taking guns out of the hands of some people accused of DV, but with some knowledge of the system, it's not hard to see why people would be against guns being taken away from people.