Homeowner did a poor job.
1. He was not in immediate danger. They were outside and yelling. It was time for a 911 call, not gun shots.
2. He obviously didn't have a a good ID of his targets. Deputy's wear uniforms. And, as Tom pointed out, it would have been a good idea to listen to what they were shouting.
3. (and this applies to the Peace Officers too) He missed. Turns out it was a good thing that everyone missed..well, except for a grazing pellet from the homeowners shotgun. But the rest of the shot and 4 shots from the deputies went somewhere else.
(actually, I'm being picky....hitting moving targets is not an easy task)
The only thing the homeowner did right is he grabbed a shotgun as his choice of weapons.
The Peace Officers....
While I don't know what works out there and don't know what their SOP is, it seems to me to be a good idea to announce you are Peach Officers while staying out of sight of the "alleged" perpetrator.
I guess they didn't know if any innocents were inside and didn't know how many bad guys there might be, so them acting without backup seems warranted.