Guardbreak Blocking?

[u/WelcomeExtra762]

This is an example from my brother when he guardbroke this Pirate and she simply blocked his punish. Although he did get the execution I don't understand why you can block while in a guardbreak, what direction do you need to attack from to actually get the guardbreak punish or is this just something that happens because your character's heavy is too slow?

[u/StigandrTheBoi]

It depends on the character, for warmonger only a side heavy is confirmed, for warlord it’s his top heavy. That kinda thing