Also any of the standard "fare" that comes with resistance forces: killing "collaborators" without trial, assassinations of high ranking officers and personnel (also without trial), etc. torture of Imperial personnel, etc. It's impossible to believe that such things did not occur.
One must be wary when applying "real world" concepts beyond symbolism and metaphor. Not saying you can't do it, it is just that they cease to be foregone conclusions in the same sense.
"Standard 'fare'" applies very differently.
It is not only possible, it is probable that such morally detestable acts did not occur in canon* as the whole system runs on GL's moral whims (with mixed results). Given the evidence, it is not only possible that the Galactic Empire was thwarted with very few (if any compromises) if pressed, GL would probably spin some heroic fluff about how they managed it.
Look no further than "Greedo shot first" to see the lengths he will go to portray even the resident "bad boy hero" in the best possible light. Even if you suspect that GL is trolling us a bit with it all, he still officially holds that line and would be apt to do so with the Rebels as a whole.
*As a side note, I am all for RPG stories that portray a grimmer Rebellion.