When I first tried a Janome I was using my GF's 6600. The stop/start bottom and reverse button are very close. Also the stop/start is red when it is stitching and green when it is stopped.
I hit the reverse button by mistake, it didnt stop. The button was red so I thought I had hit the stop button. So I started yelling at it, "stop, I told you stop"
She still teases me about that.