Water drake hp regen bug

No proof to post, but I just finished a Sejuani game with 1 water drake. I had 103 hp after a teamfight, and continued to chase because my team was in front. The entire time, I was getting 125/s hp regen while still being in combat (sivir W pokes), I went from 2% life just outside of our mid turret, to having full hp at their blue buff.