Nobody should take the blame for what happened. Roleplay is all about the journey. As Fred said, if everyone acted perfectly all the time, it wouldn't be any fun.
I figured the Kotori-C would attack anyone who was visible, and that left Tom and Rin to take the brunt of the damage. Could I have meta gamed a bit and done it differently? Sure, but it didn't sit well with me. Kotori-C hit close to home for Tom and I wanted to show that in his fear. Going invisible and shooting rockets seemed like a cop out to me.
So Fred took the initiative and beat up on Tom, then Rin, which was natural. I don't consider it a mistake because it spawned some very good roleplay in the process.
And it seemed natural, like Rin was destined to fulfill her goal in protecting the officers. I mean, the character made this a point in several of her posts before, and it seems like a fitting end to her character arc (in this mission) as it was already foreshadowed.
And, of course, Rin becomes a rallying point for the rest of the characters to try even harder now. Very good stuff!