He isn't a typical Commissar. Also I do hope by the time if you decide to take such an action you have a reason that warrants it cause thus far he hasn't done a thing for anyone to feel anything, but respect for his previous war record. He is a war hero for the guardsmen  who could be sitting on the back lines in command yet he chooses to fight on the front line with the grunts.

Prepare for blood shed if you kill Viber.

Also Viber was speaking on the ship not on the ground he was silent and standing still once people were on the ground.