This is a tough case. On the one hand it's too bad they started throwing around macho taunts. On the other hand if Mr./Mrs. Davis hadn't started a physical assault and just called the cops, they'd still be alive and maybe have an insurance check in hand to pay for the door ding.
In Colorado there's no duty to retreat and as long as you're not the initiator of a fight you have a right to respond to deadly force with deadly force (and clearly a steel bar applies).
On the other hand ... if Eichstedt had started pushing and shoving and Davis responded with a metal rod ... Eichstedt would be in jail right now for pulling the trigger.
I could have seen this going either way.
I don't know about y'all, but carrying a gun makes me a NICER guy, and a lot less macho. I'd stand up for myself, but once things started getting physical I would have descalated that situation by trying to walk away. If they wanted to call the police, so be it. I'll wait for them to arrive. (what is it someone here say ... "You can afford to have a gun, or you can afford to have a temper, but you can't afford both?" -- something like that).
But if someone comes at me with a deadly weapon I'll defend myself in kind. And since I wasn't there ... well, I wouldn't have used the same words that were reported, but I think I can yell back at someone and defend myself without having to face a beating from an iron bar.
Colorado training isn't very well definied. My own CCW class was excellent, and my "advanced NRA carry class" was even better. I think the secret is to seek out the best training possible, since they all cost about the same, and take the advanced class if you can afford it at all. Our advanced class had a real criminal lawyer come in and talk about the law and answer questions (VERY eye opening in many ways).
It's a slippery slope, though, when you start putting too many specifics into the training requirements in the law. i.e. I'm sure that the anti's would love to put in rules about taking at least 50 semester hours of training at a local college and/or having a law degree to restrict the right as much as possible and keep people from getting the CCL they abhor.
Too bad the first defensive use of a firearm by a Colorado CCL holder (at least since the new law went into effect) couldn't have been a little cleaner. But at the end of the day it appears that the guy who got shot initiated the action, was the first to draw a weapon, and that it was justifiable.