Hello Perrin, a couple of mitigating points, I think:
1. The introductory battle text states the doors were closed ("The blast doors slide open to reveal" etc). I sort of assumed they were as well, this being a private meeting place and all. Can't really fault the GM for not describing every door closing behind us, can we?
2. The first action taken by Switch's bodyguard was to form a line, specifically between us and the door. Everybody here assumed this meant we had time to get ready, and that most definitively includes your truly (and yourself as well, by your own admission).
3. Ganga's men then ignoring the bodyguards took everybody by surprise. It was meant to though. Read four posts above this: Ganga bribed the bodyguards to be on his side! We, in a very real sense, fell into a prepared ambush and were surprised, IC.
None of us were actually Surprised in a game's mechanic sort of way though, so Possum correctly supposed that as a group we were not distracted, were paying attention to our environment and had taken the necessary precautions (that would be Mack guarding the rear
). That Mack, supposedy the most prepared, still ended up reacting after the others is plain bad luck. His low initiative roll unfortunetly shows that he wasn't, in fact, as prepared and on the ball as you thought he was and/or that he underestimated the immediate nature of the threat ("we are not hostile yet and the bad guys are going to mow down Switch’s guards", or something along those lines). Contrarely to the others, he did describe his weapon as "in hand" though, so he does definitively have that on his side of the court.
That's how I see things. YMMV, of course, and I'm definitively not the final say on this type of thing (That would be Possum
). Just thought I'd share a different point of view.