In the description for Rintrah’s Root mechanic, it lists all of the various interactions it can have:

Notably, there is no mention in there of Rintrah losing his passive unstoppable while still Rooted. However, that is what is happening when the opponent throws a special attack.

Is this an intended interaction not listed in his description, or is this a bug causing his passive unstoppable to disappear prematurely upon the opponent’s special? The only synergy active in this clip is the Guardian block proficiency synergy.