To reach that conclusion for all of them, that none of these are bugs, you must think the legislature is much smarter than I think they are.

We can't write bug-free software even with unit tests and formal methods, what hope does a legislative body have? Debate before a law passes may be like code-review (and for big bills this debate is essentially "LGTM"), but most-to-all of the testing is in production: https://en.wikipedia.org/wiki/Test_case_(law)

This is not to say that no deliberate tax doges, they certainly do exist, but there's a lot of bugs too.