What is it about the word "Black?"

A funny thing happened to me in the lunch room here at work today…

I was sitting at one of the tables in the lunch room with a couple of co-workers from the art department, and we were having a conversation with this other group of people about the guys who man the security booth at the front gate. They were talking about a guy named Jimmy, and I asked, which one is Jimmy? There seems to be a bunch of different guys out there in the booth and while I recognize some of them, a lot of times there are people I've never seen before.

So, four people proceed to try to describe to me who Jimmy is:

"He's the guy with the sunglasses."
"He's the guy who drives the truck."
"You know, he's got the long fingernails like a woman's?"
"The one who always has a real (as opposed to a toy?) gun strapped to his belt."

Anyway, these people kept throwing out all the characteristics that still didn't really narrow it down for me. Finally, I asked,
"Are you talking about the black guy?" (There is only one African American security guard)

All of them answered "Yes, that's the one!", with such relief – like they were tired of trying to dance around the obvious and who is this girl who's so thick that she can't get what we're saying?

Needless to say, all of us from the art room busted out laughing – tears were running down my face – I was laughing so hard. The four imbeciles (I love that word) who were trying to describe this man to us had this puzzled look on their faces like they couldn't understand what was so funny.

Is it just me, or do people sometimes get so caught up in being "politically correct" that they actually become more offensive?