--
Cedric's words were not a threat but a promise. He's under a legal obligation to execute people who abandon their posts for personal gain, especially on a battlefield like this.
In fact, it would've been fine if he actually killed the guy because what he said was definitely treason. The army would not blame him for his actions because if they were in the same position as him, this guy would not be spared.
Seeing the coward back down in fear, nearly pissing himself in the process, Cedric retracted his weapon. He then looked at the leader of Squad #3 and said:
"This matter will be escalated upon our return to the camp. As their Leader, you should be more proactive in your role. Expect a Disciplinary Action enforced upon you..." Cedric then looked at the frightened guy, "...and him, especially him, upon our return. Of course, that's under the assumption that all of you return in one piece."