The only time I have ever seen anyone kicked over the handle bars when starting a motorcycle was on a 500cc matchless single. At first it shocked me but when the guy got up OK I think I laughed till I couldn't breathe. Then he just pushed the bike back into the building and that was that. Perfect arc from standing beside the bike to laying in front of it.
The first BSA 441 Victor would do the same thing. The first year it had 12:1 compression, you had to use a compression release to start it. One day several of us were out riding the power line trails and decided to take a break. When we went to fire the bikes back up the compression release cable broke. The first couple of kicks weren't bad but the third time I tried it throw me off. My buddy Ron was 6'4" and well over 300 lbs he got on it and started it. Needless to say after that I rode with a spare clutch & compression release cable.
I would love to have a Matchless GL750. My best friend had one growing up and I believe it was one of the last ones to roll off the line before Matchless closed it's doors.