Zac's Cell Division in URF

During URF, Zac had a mode-specific balance change that caused Cell Division to end early upon being reduced to 1 blobblet. This was not documented in the URF balance changes, but happened every time without fail.

Example: https://youtu.be/1Oj2MF3sPRo?t=18m35s

Was this a feature that shipped accidentally into URF (accidental due to how map-specific changes work)? An intentional URF change?

'cause... playing him a few times (okay, a lot), it actually felt pretty darn awesome to be guaranteed to get up - and that the minigame just controlled how healthy you were.

(That video isn't the best example because Gangplank seems to kill the blobblet at the same time Zac gets up, but I can't find any better videos and I don't have any replays of my own).