They argument does not depend in the slightest on the equality of crime rates, its depends on the their similarity. The data linked show quite similar rates of reported use for cannabis. You can make all sorts of valid counterarguments at this point.
Refuting the language used to express the argument ('uniform', 'equal') is
meaningless-to-disingenuous nitpicking of its form with basically no consequences for its substance.
That’s my point though? If the argument doesn’t depend on it, why make an easy to nitpick and disprove claim as part of it, especially if it doesn’t even come to bear on the point anyway.
I’m not the one who brought up the nitpick in the first place, so you can argue with them instead if you prefer people didn’t do so in the first place.
> Every demographic commits petty crimes and code violations at about the same rate
.. is not actually true, so better not to claim it as part of a strong argument.