I read the OP. All my posts have been critical of what he has been told about the hunt for the problem. And you are right, the probability of the problem coming from Break-away-switch is 0.
And the chance there is a issue with driving style might be pretty good, but that is not the only problem.
3 out of 4 brakes wore out. Fact is 25% of brakes not working will cause rapid wear to the ones that work.
And once he has looked at the shoes, he knows which wheel has the problem. And if somebody that knows what the are doing replaced them, about the only place the problem can be is electrical, and in the branch going to that wheel, or ground.