(Strictly sports/competition guys might find this useless.)
At my school the instructors like to sneak attack each other. Yesterday afternoon my friend Matt & I were walking back to my car in the parking lot of a grocery store when suddenly he was grabbed from behind & the bag he was carrying was also grabbed.
I did a double take & saw that the attacker was the owner of our school & thought, "Oh, thank god, its only Jeff...OH SHIT, IT'S JEFF!!" Because Jeff would happily take my groceries & drive off if he thought we didn't put up a decent fight.
I was moving to help Matt (& stupidly not checking behind me first) when I was slammed from behind & my purse was grabbed by this other guy we work with. I mean that purse was off my shoulder & gone & he was too far away to catch before I even realized what had happened. Once I realized I might not catch him I thought, "Screw it, Matt's more important" & turned to help him, but it was already over.
The whole thing took maybe 3 seconds.
The thing I observed about myself was that my immediate reaction wasn't fear or anger or aggression, it was confusion. First confusion about what the hell was happening to us, then when I realized who the attackers were, confusion about how to respond since I couldn't really go straight to total destruction like I've been taught. 3 seconds of confusion, & by the time I decided how to attack Jeff it was too late.
Not how I thought I'd respond. Don't know if you can put this to use in your classes, but I thought I'd share just in case.