I disagree about the you don’t have to part. You can, and you should explore these dialog options if you feel like. They are part of the game for a reason. It’s role play. This was just a standard conversation option with an NPC, and it also had an option to resolve the conflict it created.
The option to convince the guards that you are good was functionally broken. Gamoo explains that as well in the post above. The point is, it’s a bug. It’s far from perfect.
Also bugs: You can (at least we constantly ran into this, even recently) also lose romance options because of events that happen at long rests. They overwrite the romance events.
The mage tower quest, one particular and important NPC was stuck and didn’t even have a turn in combat. Just T posed there. Reloading the save did not help.
That said, the game is great. Just not perfect.
…an espresso?