Am I Liable To Pay For The Damages (iowa)

So a week ago I got into an argument with one of my friends and it turned into them provoking a fight, things were said and he got about a foot from my face (still trying to provoke a fight) so I pushed him back to get out of my space. As soon as I did that he started to hit me and got me real good on my cheekbone where I had swelling for a few days as well as a bump on the back of my head from my head hitting the wall that lasted just as long. I don't remember much after the first hit other than having him by his shirt collar before getting separated after we were separated everyone there noticed one of his glasses lenses fell out and the frames were damaged. now a week later he's trying to claim that it was me who had damaged the frames when I grabbed onto his collar and is trying to have me court-ordered to pay for his frames and lenses plus other court and lawyer fees. I don't know anything about Iowa law, am I liable to pay? Would it just be easier if I just paid him for the replacements out of court?