[Gameplay] Can't interrupt baron empowered recall?

I was playing as Morgana and saw Malphite recalling after taking baron. I walked up, W and Q'd him, but he still managed to recall. I actually saw him being hit by the snare and w and the recall animation still going for maybe ~1 sec and then it completed anyway. I went back to watch the replay to double check that and sure enough he channeled recall for around a sec after getting hit. Not sure if this is a one off thing or not.