Having a husband that had a stroke
about 1 year ago, I can tell you that sometimes he just blurts things out that can be offensive to people. When I quietly remind him that he should not say such things, he is very surprised at what he said and is very apologetic. My husband also has a tendency to repeat things, which can be annoying if you don't understand why he is doing it. If you are this mans friend, I would suggest that you talk with him about his behavior and see what type of reaction you get. If its one of surprise, he may be totally unaware of what he is saying. If he appears to know what he is doing, then he is having problems with self-control. Talking with family members may also help you understand his disability
more. Management should be careful about letting him go, as the man is disabled and there are laws about discriminating against persons with disabilities.
Having a 52 year old husband with lingering disabilities from his stroke has made me much more tolerant of disabled persons. I find I am much more patient and understanding. Maybe if someone reminded your friend that he was being offensive and quietly reminded him that he can't talk like that or sing bawdy songs, he will refrain from doing so and gain more self-control.