Maybe he's very good at setting up cantilevers. There's no magic, just physics, cantilevers can be as good as V-brakes when first installed, it just takes hours to dial them in and then they go out of adjustment the first time you use them because the pad wear has a much more dramatic effect on lever ratios than it does with other brakes.
A 7 year old child can set up mini-Vs - that's no hyperbole, I literally got my 7 year old nephew to fit mini-Vs to my brother's bike.
Maybe he's very good at setting up cantilevers. There's no magic, just physics, cantilevers can be as good as V-brakes when first installed, it just takes hours to dial them in and then they go out of adjustment the first time you use them because the pad wear has a much more dramatic effect on lever ratios than it does with other brakes.
A 7 year old child can set up mini-Vs - that's no hyperbole, I literally got my 7 year old nephew to fit mini-Vs to my brother's bike.