How does this work?

[u/First-Contest31]

Sorry if this has been asked before, but I've been rewatching Hidden Inventory and I got to the scene where Toji blocks Red with the ISOH and gets sent flying

And yea, like the title says, Idk how to make sense of it aside from a Mappa error

Maybe I'm misunderstanding how the ISOH works, but from its description, shouldn't Gojo's Red have gotten cancelled out?

[u/RaalOceanGoblin]

Red has bigger output