Ok, so this is interesting, and we have video evidence.
So the individual who was PK'd entered the ICC through invitation, and left through invitation, so there's no natural assumption of hostility to that point. He's clearly walking and not running, and he's not going for the ladder, he's going to the gate. So we have to assume he didn't believe he was under duress. In addition, at no point do either individuals look behind them or turn around, so we have to assume they only could see what was infront of them.
At 04:00 what is infront of them is one individual with a weapon vs 2 individuals with weapons drawn saying "you're being detained." At that point, he has a good argument that he's not under FearRP. He can reasonably assume that 2 v 1, he can win that situation. After hearing "you're being detained, he walks 4 steps, for a total of 2 seconds before coming to a stop. During this moment he's radioing in. He then turns and sees another individual with a gun on him, making it a 2 v 2 situation, still not overwhelming odds in Fear RP (you could argue SMG vs pistols, but I don't think that's how the rules work). He cannot at this point (06:00) see the third individual and he does not turn to face that individual. By 07:00, one second later he is at a complete stop and abiding fear RP. He's told shut up, and stops reporting on his radio.
Less than one second later he's killed...
I've been playing this game mode for many years. I have a guard unit attached to me, and I've played many times, factions that arrest/kidnap etc. people. I have traditionally, and my guards currently have a 10 second timer to react to fear RP. Now it doesn't always go the full 10 seconds, but usually an individual has time to stop and react to Fear RP. Sometimes they use their radio, and in those instances tradition dictates that the individual is tied and the radio either taken or turned off.
In those instances, we're talking about 10+ seconds of RP. This entire instance is less than 2 seconds of RP. In addition, the Kommodore dies (assumingly instigating the shootout) and faces NO PK.
If we want to set the bar to a 1-2 second reaction time, that's fine, but like the tax code, i'm going to use it in the future.
+1 UN-PK
Also, my involvement is that I witnessed this coming out of the sewers, and spoke to both parties on scene who both agreed the PK was a mistake.