Ignite Problem?

So I ignited a guy as Tryndamere and stayed on him hitting over and over while my ult was on. I die but somehow he lives despite me both igniting and getting one AA off on him. Can I have an explanation as to why this guy lived? I mean how does someone live when ignite negates half of the healing? He doesn't have spell vamp and health pots could no way heal him that much. he doesn't have a shield ability. how on Earth does he live? He literally had like 200 hp left. Ignite and AA should have killed him. He doesn't even have the heal summoner spell. I really want to know how this guy lived. Can someone enlighten me? We were not near any turrets. This was us in the Jungle. I was fighting a Brand. And yes I did ignite him because my ignite went on cd and I saw the mark above his head. Please someone enlighten me on what the hell happened.