Years ago I didn't employ a guy with a stutter, but not for that reason. I called him back to explain - he thanked me and we chatted for a while. I said had he had major problems with his speech impediment - only once.

He had become friends with a man with a similar impediment, and they would laugh with one another at their problems, 'til one day a car pulled alongside them, and the driver said "C_C_C_Could you D_D_D_irect..."
It took twenty minutes to cool the situation down.

Stu