I just wanted to point out that we can already attack Gale when we first meet him, and all he does is appears.
Gale, Lae'zel, Shadowheart ... everyone can be attacked right from the dialogue ... Shadow even attack you and fight to the death, if you play Gith ...
This whole scene with Astarion seems like Larian inspected their numbers, find out that too many people killed Astarion right there on a spot ... and decided to not allow it ... wich is pure definition of lazy writing if you ask me. :-/
