Will a health insurance co like Kaiser come after me for their portion paid out on a small injury?

My cat lightly bit my young neice and my brother in law was worried and took her to the ER to see a Dr, since it was late at night on a Friday. Everything was ok, my cat doesnt have rabies, etc, and they gave her antibiotics to avoid any possible infection from the bacteria on the teeth and it looks like the scratch is fading already. My brother in law is cool and didnt ask us to pay for any of his co pays, etc. He has Kaiser, and my question is, will Kaiser come after me for the portion that they paid out for the ER visit?