...Get thrown from a horse, gun stays in the holster, you gotta winner.
This is a very good concept to envision and it applies to me as I carry mounted. Along the same lines, and not exactly related to the topic, when on horseback, it's prudent to carry all your survival stuff (gun, phone, knife, space blanket, first aid etc) ON YOUR PERSON. If you carry it in saddle bags, and get thrown, the horse could leave, taking the essentials with her.
Perhaps there's some comparison there with motorcycles, cars, what-have-you. I guess your motorcycle won't likely throw you then drive off. But it could go over a cliff, under a truck, through a glass window etc.
All my stuff's in my Sam Browne or boots or serge -
Sgt Lumpy - n0eq