I have had cars on the dyno, and never worried about it. But I don't stand next to the car either. Not scared doesn't mean stupid.
Think about it.
But look, here's a story for you. A Guy on another forum has a MORBID fear of flying. Has had it his whole life. Other forum members talk him into taking a flight to ''cure'' his fear. Plane crashes, everyone dies.
And the moral ? If it REALLY doesn't feel right, DON'T DO IT !!!
No, I am not kidding, I'm trying to be helpful. Now move along.