Well, by the picture, Sollozo is dead, McCluskey, perhaps at his last breath, and Michael, well, his whole demeanor, if you recall is "calm". He simply stood up and shot.
As for the waiter, looks like his eyes are closed (perhaps in fear?).
To be honest, if I hadn't seen the picture just now, I wouldn't have remember the waiter standing right by the table. Good picture though. That's one of my favorite scenes.
TIS