In round 8 he smoked off the spike and used his astra pull before defusing.. so when the enemy astra pulled, it wasnt able to get him off the spike.
BIG BRAIN ASTRA MAIN
I mean he was the same guy who did the crazy Zarya graviton play during the first world cup in overwatch , he's always been a brainy player in my eyes and you can see that experience from overwatch carry over , he can multi-task and manage his utilites like a boss .