He doesn't know how to argue with this, and not in a way that makes him feel like he must be wrong. Instead, it's all too easy to imagine how their side of the story would be just as bias as he's sure that Megatron's, to some degree, is...that's just the reality of history. But as such, nothing she tells him means anything. It all comes down to who he personally trusts the most.

And Megatron...

He trusted him more than anyone, perhaps besides Alpha Trion.

"He was the head of a revolution intended to bring freedom and justice to those that did not have it," he says, trying to remain calm, but with an intensity that shows through the cracks. "And I sided with the ones that enforced the regime that took it away from them. I have no evidence of what I had reason to stand against when I should have been at his side."