Ame

I have experienced the engine switching off while riding, fortunately I was on a low traffic road!
I think this is what happened in my case:
the side stand is a heavy & long piece of metal and the srping holding it in place is not strong enough.
when up, depending on your shoe size and riding position, you can brush you hill against it and trigger the stand switch which is what I think happened as I was going over a speed bump.

You will also notice when down, the stand is not firmly held and can easily come up