I Fully agree that tubbo thought he was doing the best that he could with the information that he had, that tubbo was being actively manipulated and lied to by dream, And that tubbo's reaction to tommy at the time was fully understandable
but I Do have to protest the idea that dream's demands seemed Reasonable At The Time, because part of the whole point is that it Wasn't.
dream's Original demands were that tommy should be exiled until he was 18, 2 years !, for a crime that was as common as breathing on the smp.
the conflict between tommy and tubbo during the trials was Not that tommy had done something wrong and was now refusing to cooperate with dream's seemingly reasonable demands (that Only read as off in hindsight) for his punishment.
the conflict is that Tommy could clearly see that dream was being unfair and was trying to refuse taking dream seriously because of it, and was upset in turn when he wasn't being backed up.
while Tubbo was upset with tommy for not being willing to put up with it for the sake of the rest of the country.
it's that tubbo was fully aware that dream was capable and willing to escalate the situation (lets not forget that the final control room was the biggest mass murder on the server at the time) and that tommy being difficult was just making it harder for everyone else. while Tommy was standing by the fact that the situation was Weird and Unfair.
tommy didn't want to give dream any ground, to let him overstep and undermine the protection from dream that l'manberg was supposed to be giving them, and tubbo wanted to let something comparatively small go so dream wouldn't Escalate into taking everything again. and in the end they were Both right in a way, but there was no way to thread the needle and choose the Correct option to save l'manberg from dream. and both of them were hurt by the other not seeing what they were trying to do (preserving l'manberg's Spirit vs preventing conflict).
and that's the thing, the situation was intentionally manufactured that way. even if tommy had behaved Perfectly (unlikely, considering it's tommy) dream had Already been intentionally framing tommy for griefs and would Continue doing so in the future. if he hadn't made trouble during the trial himself then he was going to Look Like It either way.
and, of course, the whole point of dream making himself out to Seem reasonable if you don't look at the details too closely was to sow those feelings of doubt and isolation. because of Course the situation wasn't fair, how could nobody see it but him?
which all becomes Especially clear with ranboo fully admitting that he griefed with tommy, that tommy was trying to take the fall for him, and getting absolutely no flack for it whatsoever. because it was never About the supposed crime, it was about tommy