My experience is that the Adidas houg has be nailed, hard to even register. I can not imagine that bumping hogus would register, unless it was set on junior fly and adults were using that setting. We have never experienced that with the set we have.
I've rarely seen it happen, certainly not with just "bumping;" but when people offered that reasoning as a "problem," my response was that IF the illegal technique was that strong, it SHOULD register, and then that requires the deduction and point removal. The Adidas Hogul would require a sincere application of the illegal technique rule, which I thought was a "plus" if and when it happened.
In our three years of training with it, we like it because 1) it is simple, 2) does not require additional equipment socks that wear out, 3) is consistent, and 4) uniformly scores the variety of legal kicks (i.e. back kicks).
My experiences with LaJust were negative, period. Daedo, OK, but the simplicity of the Adidas system seems more consistent with uniform results over the lifetime of the equipment.
Unfortunately, WTF went with the idea before the technology was demonstrated sufficiently reliable and consistent. It was a triumph of politics over reasonableness.
-- Bagehot