I've been umm'ing and aah'ing about posting on here for the three days it's taken me to skim through 12 pages of comments... First observation about the OP is that this is one side of the story, and doesn't really talk too much about the atmospherics of the conversation. Both allowing, and not allowing the T/L could be 'Play Casual' depending on the way that is communicated. Similarly either decision could be communicated in a way which would mark you as a ****. Other people have said something similar already, but it's not the decision being made, it's how you talk to and treat your opponent.
I believe it was the saintly Rick Priestly (he was a big cheese at GW for a loooong time, but don't hold that against him) that said any game is a social contract between the competitors that everyone will have fun. That's why we play games. Of course we want to win, and how much that's important to you will vary, but if one or either of the players goes away with a cloud over their head, then both of them share some responsibility for it not being enjoyable.
Personally I never ask for take backsies, but will offer them if I think it was a brain fart. I would like to think the same would be offered to me, but I certainly wouldn't mind if it wasn't.
Oh, and I also think it was a bit cheeky asking to shoot your ship out of sequence when you made such a big deal of the missed AS action.