read fast and out loud

I had a boss who has a sister who is mentally handicapped. One day an employee was "imitating" and making fun of handicapped people. My boss went off on him and fired him on the spot.
There are tons of things to laugh and joke about, but someone's health and mental state are not one of them IMHO, especially when its beyond anyone's control.
I personally think its in poor taste , but that's just my opinion