I can understand the need for third party.
Last summer, after taking a wrong road, a nice old gentleman staggered onto the lane I was on and was very kindly explaining which way I should go. I accidentally caught the throttle on my bike which leapt forward and I only just managed to hold it back as the tyres caught the old chap in the chest while the bike did a quick arc through the air. He staggered for a moment, said nothing about the bike but continued telling us where we took a wrong turning. It could have turned out so much worse or if I had listened to my wife and switched the bike off. so much better.