>>514125278
How did you miss the point so badly? You weren't killed on a technicality. The Thalmor intercepted Tullius on his way back to Cyrodiil to hang Ulfric. It forced them to execute everyone then and there otherwise the Thalmor would've taken the Stormcloaks and "accidentally" let them go. The game outright gives you this information.

You're only being executed because the Stormcloak rebellion is a Thalmor honeypot to keep the Empire divided and weakened instead of turning their sight back on the Aldmeri Dominion now that they've recovered from the war. The only two reasons to ever side with the Stormcloaks are:

A) You're RPing as a Thalmor attempting to keep Skyrim from reunifying with the rest of humanity.
B) You're playing the stupidest nigger that ever nogged.