I don't think you're over-reacting at all and please don't think this is pointless. If this concerns you, and it obviously does, it needs to be addressed. You did the right thing bringing this to your PT friends.

Have you tried talking to him about his attitude towards cats and why he's so negative about them? Your sweetheart is a member of your family and he needs to understand her place not only in your home but also in your life.

I wish I had the definitive answer for you. The conversation is started and, knowing the PT folks, a workable solution will be found.