I've made "Rodinal" a few times from scratch from the formula Photographers Formulary has listed in the .pdf of their kits. I've never had a problem and the homemade solution development times are the same as posted Rodinal times.

In the .pdf Formulay puts out for their "Rodinal" they do mention that they provide extra potassium hydroxide. It's simply not dump the chemicals together. The B mixture has to be added very slowly so that the milky white liquid can slowly change to it's red-brown color. Without seeing how someone mixed up the kit, it's impossible to tell whether the kit or the individual is at fault.