Absolutely not. There is no question that a law abiding citizen has the right to arm themselves when facing what appears to be an aggressive and unknown threat within their own home. The onus is on the LEO who is supposed to be a professional and well trained in threat assessment.Question, is it reasonable for an officer investigating a domestic disturbance call to believe someone answering the door with a gun in hand is going to shoot them?
Even if he had the right apartment, that officer had no idea if the man holding the firearm was the aggressor or the victim holding off his attacker at gunpoint, right?
It becomes a real slippery slope. What's next? A cop responding to an armed robbery at a grocery store mistakenly shoots an innocent that was open carrying and we are going to say, "Well, that was stupid of him to be open carrying, hu!' (??)
There are what? Something like 150million law abiding citizens with firearms in their homes? A good chunk carry. What's "reasonable" to assume is that an LEO is going to have encounters with armed law abiding citizens as a routine matter of course. The mere presence of a firearm, in and of itself, does not constitute a threat.
I don't believe a, "when in doubt, shoot to kill" LE approach is in any way "reasonable", but that's just me.