I don't seem to have that problem. Do you really need Canon to come up with a solution?
Canon used to use a lock button on the mode wheel.
My old Elan has one. However, there were a lot of ham-fisted people who would somehow forget about the button and twist the wheel hard enough to break it. The biggest point to watch for when buying a used Elan was to make sure the lock button wasn't broken--that was the very common fault of used Elans.
If it's not there, it can't be broken. If it is there, some people will break it.