A great example is price reporting to the gov't. You're supposed to report your net price across all sales to CMS on a quarterly basis. Problem is, the regulations are so vague that it falls on companies as to how to interpret them. Naturally, companies err on the conservative side (at least most of them). My old company probably had 20 FTE's dedicated to this one regulation.
And if you reach out to the regulatory body for clarification, that's a multi-year process. A great example is the AMP rule (average manufacturer price). I think CMS was supposed to role out the clarification back in 2012, but only finalized it last year. And there are still unanswered questions.
When asked for the specific rule we had to follow, there was never any response.
When I asked whether SOX compliance really required this they basically said they didn't really know but had to play safe as the regulations were just so vague.