I personally never heard him do it, but when I was coaching in the late 1970s there was a coach at another DI school who was renowned for telling--loudly--a lagging xc runner, "If you can't run faster than that GET OFF THE COURSE!" The coach was deadly serious and other spectators didn't comment at the time, but they practically pissed themselves when retelling the story.
And one time I had an athlete in the late stages of a track 10,000 who was being inexorably cut down by another runner. My guy was on the other side of the track when his opponent caught up and went to pass him, and I was yelling vigorously, "Hold him off, Howie!" And when that didn't work, "Check out and go with him!" And, when it looked like that wasn't going to work either, under my breath I added, "Spit on him!"
Except I guess it really wasn't under my breath enough, because half of the students who were in the stands with me gave me that "did he really say that" look, and the other half (who knew me better) were laughing themselves silly.