Then, unless the block feature breaks connections between instanced players when it is used (which I don't think it does), the attacker must have blocked the other player prior to instancing with them - which implies that they knew who they were already and could select them on recent contacts to block them.
I really do not know how the attacker was able to block my friend while already in battle with him, but I am talking about what I saw and what the attacker did not deny.
Is there anyone who has experienced this? Someone was effectively blocked while already in the same instance?