My father and I haven't had contact in years. He kicked me out when I was 16 but he agreed to keep me on his health insurance until I started getting my college health insurance. In September of 2019 I started college and got on their plan and he said that I'd be covered until September or October 1st of that year. I blocked him on my old email and he doesn't have my number so he emailed my mom sending her photos of some medical bills in my name that have been charged to him and asking if I've covered it. I gave my mom my new email so he could message me and he said that he's mostly worried about one that's over $1k charged on August 2019 and a $300 one charged November 2020 (which makes no sense to me). I told him that I'd call the hospital that charged the $300 one but the $1k bill was while I was still under his insurance.

I'm sure he's going to try and get me to pay the $1k bill despite me being under his insurance at the time. He also stated that there were other bills from 2018-2019 that weren't paid, again, all bills that were charged when I was either a minor or the few months I was 18 and still under his care. I know that he can't make me pay the bills from when I was under 18, but I'm worried that he can try sueing me for not paying the $1k bill despite me still being under his insurance when it was billed. I have no doubt that he's gonna try, that's just the type of person he is. But I can't afford $1k right now nor do I want to give him the satisfaction of making me pay for something that is his responsibility. He has scared me into doing certain things before with the threat of suing (even if he couldn't) so I want to make sure I'm 100% in the right here before I tell him that I'm not paying it. If I'm wrong, I'll still gladly put the bill on my record, I just don't want to if it's not my problem.

Edit: I'm in oregon, he's in Arizona.