Ignite does more than tooltip says?

No screenshot, but was playing a game as Zac. Support Brand ignites me in a level 3-4 fight. I die and on the death report it says that ignite from brand did 555 true damage, about 45% of the damage that killed me (almost full health). Ignite's max damage is 410. Brand proceded to do metric craptons of damage that game but I just assumed that was just good base damage.