Kog'maw changes don't match the patch notes

The patch notes stated that Kog'maw's W (Bio-Arcane Barrage) now deals an additional flat 5/10/15/20/25 magic damage, increasing with ability level.

In actual games, however, the tooltip on the ability states 10/15/20/25/30 flat magic damage (5 more starting at the first point in the ability) and by my math these are the actual values being used in calculating damage (against a level 1 Alistar with 689 max health and 32 MR I was dealing 17 magic damage per hit)

I didn't get a chance to play Kog'maw before he was taken down due to a bug, so I'm not sure if these values were introduced with that bug fix or if they've been like that since that patch was introduced.

I feel like Riot meant to implement the patch notes version (lower damage) as Kog'maw really was calling for a nerf yet even those lower numbers were coming out in my math to just about break even with Kog'maw in the previous patch, perhaps even come out ahead in levels 3-9 where a nerf was most called for, and scale even harder later on in the game.