Both of those statements are somewhat insulting, and Optimus is not in the mood to be as good about tolerating that kind of crap as he'd usually be. There is no sudden flash of anger as his optics narrow - more like, for a few moments, he tries a little less hard to force his emotions into check.

"Do you doubt my ability to do what is necessary, then? Are you really so arrogant as to assume that you know better?"

His voice is a rough growl - he doesn't raise his volume, but he's rarely needed to in the history of his command.

"You underestimate the burden of command, and to so willingly make such a task harder for your fellow bot demonstrates not only selfishness, but a pivotal weakness of spark. Arcee had the weight of the world placed on her shoulders regardless of her own desires, and you disrespected both her as your commander and teammate, but me as her appointer."

"This is no minor betrayal you have taken part in, Rodimus. And you will be penalized accordingly."