Don't know the particular tax law in question, but perhaps it would help you if you thought you of lawmaking as making software (in fact in French the word for law is 'code')

Everything you code has to be coherent, requirements change, and when they do it is hard to get everyone to agree on the details. You have 200 years of legacy code, have to be compatible with other states and countries, have to support all possible edge cases, and your code is interpreted not by a computer but by a human.

Are there broken laws? Sure. Is it easy to make good ones? Not so sure.