Absolutely not. Hot Rod's actions were impulsive and stupid, even if the best of intentions motivated them, but I personally don't think the Autobots should do battlefield executions period. Say what you will about realism and justice and whatnot, but somehow I don't think Optimus Prime would be okay with Hot Rod being killed for recklessness. I mean, when Ironhide recklessly chased after the retreating Decepticons in the pilot three-parter, Prime laughed it off afterwards. I don't know that Hot Rod deserved to become Prime, though, but that's a different discussion.