What to say post shooting
Typically, the only thing to say after a shooting, even for LEOs and off dutys is a public safety statement:
1) Shots were fired
2) Approx. direction of shots
3) # of suspects/vehicle description
4) Where'd they go
that's it. The first two are to ascertain if anyone else may have been hit (in homes, bystanders, etc.). The last two are to find the suspects that caused this DF encounter.
As for gun-in-hand scenario. Pretty simple. Do not, if feasible, have gun-in-hand. Holster it, when tactically safe or officers are on scene, and obey ALL commands slowly and deliberately. Period.
Nothing is 100%. You may follow all above advice and still get lead poisoning. You may follow none and get a handshake. Best to play the odds of survival.
Life's tough. But it's tougher when you're stupid.