IAD check-in mishap vent

Just a light vent from check-in this morning - As I made my way to the Premier Access bag drop, and United employee pointed to the sign and said pretty bluntly, "Sir, this is Premier Access."

Me: "I'm aware, thank you." [flash smile, continue walking]

E: [louder] "Sir! This is Premier Access only."

Me: "I know. I have Premier-"

E: "Yeah, but you have to ask."

Me: "Ok, you didn't say that."

E: "Yes, I did. You can't just walk in here."

Me: "No, you pointed at the sign and said 'this is Premier Access.'"

E: "Because you need to ask so we can check your boarding pass."

Me: "So next time, maybe you should start with that and a 'good morning.' Maybe try being polite."

E: "Oh... sorry..."

I've used the Premier Access line at IAD many times before, and never had an employee stop me on my way to bag drop, nor be so dismissive/rude/argumentative. I'm not particularly upset, it just could have been handled better and I have no one else to talk about it with as I'm traveling solo.