Let me just do a POV of the entire situation, since a short one about the specific scenario isn't enough.
We went to Zalesie and found Operation: Yggdrasil there with a Humvee. We initiated on them and I drove the flatbed in front of the Humvee to stop them from driving away. I believe that two of them decided not to comply and we took the two others hostage. After talking to them for a while inside the church we take gunfire from the hill, we tell the hostage to relay a message that if this does not stop, they would be executed. We continued to take shots and one of the hostages then got killed (since our demands were not met) After looking for the person in the woods and taking more shots, we decided to just leave town. Shortly after the Humvee leaves they start taking fire from an ambush. At that point I tell @Eagle to get the BMW we found in the woods out of there and I would take the flatbed. I go to the Flatbed and tell the woman in town that she can keep the other car and then jumps in the Flatbed and leaves. Shortly after leaving I hear that the Humvee saw a Flatbed with multiple people inside in Topilin, so I take another route. When going down the road i hear that @G_DateLR and another person are taking shots near Zalesie after trying to get the car I handed over to the lady out of the town. I keep on driving and gets followed by a red BMW for a short amount of time. I make it to the prison, park up the Flatbed and move some supplies inside, shortly after @G_DateLR shows up in the VAZ and also goes inside. @Eagle then tells me that he broke the BMW and I decided to wait for restart before going over to him. After the restart I head over to @Eagle with a spare radiator and after fixing up the BMW we start heading towards the prison. When we were just outside the perimeter of the prison someone yells ''Taking shots, taking shots'' and I hear bullets snap. I let eagle out to open the gates, so that I could drive the BMW in. I believe @G_DateLR then starts taking shots. After getting inside safely we RP a bit with the hostage and arrange some loot. We then hear the grenades go off and shots being fired outside the prison and we all get into positions, shortly after I walk into the room with the hostage and tells him to go on the radio and say his final goodbyes and so on, he does. We wait around for a bit until all the shooting and so on stops. We then all decide to execute the prisoner via firing squad, but he was AFK, so we acted at if he was sleeping. After waiting for the hostage to wake back up for a good 3-5 minutes I decided to go into the helpdesk, seeing that I think a rules was being broke -> Griefing. I talk over the scenario with @JobScholten and @Knightblast we talk it over for a while and I then decide to have @Watchman pulled in to talk it out, instead of making a report instantly. After him admitting to it being him and him leaving the channel abruptly after saying the words in the video, I returned to RP'ing. During the time I was in helpdesk, me and @G_DateLR pulled the remaining two wheel off the Humvee and I headed inside. During the time of me being in helpdesk the hostage was also taken upstairs to be executed once again, but I left to focus on the helpdesk situation. I ran around the prison for a solid few minutes looking for the hostage, since I thought he was already executed or we were going to execute him like the plan before me going into helpdesk. I failed to find him so I ask were he was, since I got the vague answer of ''He is upstairs'' I search through the cells of the top floor were we previously had him. I then hear them talking about letting him go and something about him bringing us a Humvee in return. My character was not happy about that, seeing that his men shot at us in Zalesie, failed to listen to our demands, ambushed us multiple times and since we assumed that it was them sniping us and throwing grenades at us, plus the fact that I knew that he was never going to bring us a Humvee. I then tried to pinpoint his location and find him, I spot him and some of our men on the stairs, seeing that some of my comrades apparently wanted to let him go with a fake promise of a Humvee, I decided to shoot him dead.
As you can see in the POV, we had MORE than enough reasons to execute the hostage, both according to the rules and IC'ly. We simply didn't act upon the OOC knowledge gained doing the helpdesk situation, he was going to be executed a total of two times before the situation in helpdesk was even over and could have been executed many more times. We could have executed him right there and then at Zalesie, doing ambush one, doing ambush two, during the multiple times we were being shot at at the prison, when grenades started blowing up and so on, but we decided to focus on IC information and RP instead.
It would IC'ly had made absolutely no sense for my character and for the group in general to let him go after what his men had done.
Since no one had attacked the DAYS prison prior to this situation, it would not had made any sense to be anyone but Operation: Yggdrasil who attacked us, so no meta gaming was used there either. Of course it could have been another group, but in this specific scenario we had just attacked them, taken one of their men hostage and executed another, so it would make perfect sense to be them, our characters simply assumed that it was them and even argued weather or not it could have been An Pobal or them before I even went into helpdesk, but we decided on it being Operation: Yggdrasil. So again, we could not be 100% certain that it was them, but IC'ly we assumed at that point in time.
I would also like to point out this part in @TheBar0n POV. ''While at the prison I was instructed not to tell my companions were I was on the radio but to stop attacking, I of course complied with that request.'' So his companies were already told, yet again, to stop attacking, which leaves us with even more rights.
From me finding out that @Watchman and Operation: Yggdrasil, that was doing it, to me executing the prisoner was properly around 10 to 20 minutes, if not more. So no, I didn't get the information and went straight to killing the hostage either.
Lets also note that I waited roughly 10 to 15 minutes and was told that the suspect ran away, before I went into helpdeks and talked to @JobScholten. The only reason why I joined helpdesk was because I thought someone was breaking a rule, aka Griefing. And again, wanted to talk it out with the person instead of making a report.
I simply don't see why I would execute the prisoner based on OOC knowledge when I had plenty of IC reasons + the rules on my side.
I don't see where the Meta Gaming in @G_DateLR POV was either. @Watchman if you are referring to this part -> ''After leaving HD @Mystery goes to the hostage and kills him'' after leaving HD, could be a span of 1second to 5days, he simply stated what I did after. As explained above, the hostage was killed 10 to 20 minutes, if not more time after me ''gaining'' the information that it was you and Operation: Yggdrasil.
Seeing that this report most likely will lead to nothing and the possibility of people getting points for rules they did not break, I would like the report closed if all parties agrees.