[GAMEPLAY] Master Yi Invincibility Gamebreaking Bug

The bug only occurred once and I've never seen it before, although it could be subtle in other cases where less damage is taken. Ezreal ults from base, hits no targets before hitting Yi, therefore the ult does maximum damage, which according to the tooltip was 567 magic damage before calculating the ~40 MR Yi had. Looking at the bottom corner at Yi's health, you can see he gains 30 health from W'ing, which would be the 30HP/s heal on his skill. The only way this makes sense would be that the Ezreal ult did 0 damage.