The update I read this morning makes it look like the guy's got some 'splainin' to do. I know it's still early in the investigation but to draw and fire in that situation seems questionable, especially if the injured were because of errant rounds. Being LEO, he should know this but sometimes emotions take over. Hopefully, there will be follow-up on this. As a permit holder, you always want to learn from such events. I'll bet the OP will think of this for a long time. I know I would.
Emotions certainly take over especially when he had his young child to protect. No reports on the kid he was reportedly holding? That would definitely amp things up for me.
...and then I find this in my email... https://www.usconcealedcarry.com/blog/anger-and-guns-bad-combination/
A punch alone would probably be considered simple assault, and does not rise to the level of "forcible felony" which justifies deadly force, at least in FL. Of course, circumstances are everything, if the punch was associated with a robbery attempt, carjacking attempt, kidnapping or sexual assault, it then becomes a forcible felony. This is why if you ever shoot someone, you should have a good lawyer you can call immediately, or you'll be the next Treyvon Martin situation.