He was given a key to my room, and came up unescorted. They had come up to my room prior and knocked to no answer. Said since I had the "do not disturb" sign up they knew I was there and felt it appropriate to give him the key to check on me.
Now, I always assume the do not disturb means "leave me the hell alone," but I guess not. I really did appreciate them giving my key to a coworker to come see me sleeping in my underwear.
It wasn't like the meeting was an important, big deal thing. We're traveling together and he said - hey, let's get some lunch later (no set time). I decided I'd rather sleep than eat, and didn't have a way to contact him as we're at different hotels and have no cells. I spoke with the coworker and let him know of the need to relax and calm down instead of freaking out. Guess next time I'll leave a note with the front desk, too.