[Bug][Ability] Rengar's damage multiplier doesn't seem to match the tooltip numbers

So first of all I am not sure this is a bug, but when we read Rengar's ability it mentions that he benefits from a damage mutiplier as he leaps then gets a 6 seconds attack speed bonus. The ability mentions: Damage Multiplier: 210% / 320% / 430%

I am not entirely sure how the multipliers are applied in the damage calculation but when I compare his AA damage and his leap damage, even at Rank 3 it's closer to a 133% than a 430%; not even close from the Rank 1 210%.

So is it intended? How is it supposed to be working? Is the damage increase correctly applied?