You have been cited under § 1.09 of the Public Courtesy Code: Stoppage at the Head of a Stair
NOT AT THE TOP OF THE STAIRS.
You climbed the stairs, reached daylight, and stopped there to get your bearings — at the exact point where forty people behind you have nowhere to go and no way to slow down. Three more steps. That's all anybody is asking. Three steps and you're clear.
This is not a fine. There is no fine. Think about what you did.