After watching the videos, there are many things to consider
For example, when he robbed you, how long ago was that before you kill him?
Correct me if I am wrong but there is a time limit where you will have re-initiate again [3 minutes/5 minutes]
Plus you told the poor guy to put his hands up and then just said shoot him, your initiation was pretty poor.
"Can you just do me a favour, put your hands behind your head?" 0:55
"Yeah, you can kill him" 0:59 - No you cannot, you told the man to put his hands on his head that is not a good enough initiation. You must threatened his life such as "Put your hands up please or you will be shot".
You did threaten his life at 1:05 but you just shot him anyway...You could've said, "Alright, because you just robbed me off my money just now and threatened my life, I will know execute you for it. Do you have any last words?" or something along the lines instead of "Put your hands up" "Shoot him, you can kill him"
In, the TCK's situation, the officer initiated and the rebel was threatened with force, TCK retaliated by killing that poor guy [quite a deep voice].