No, I disagree. There's no coding rule that says you don't code something if the provider documented it in one place but not in another in the record. Actually, in my opinion, it would be incorrect coding to omit or fail to code a documented diagnosis and procedure for this reason. If anyone tells you there is such a rule, then they need to show it to you and give you the source. Honestly, I'm not sure why anyone would tell you to do such a thing - make a procedure that provider performed and documented 'not billable', thereby deciding that the provider should not be paid for their work - because they wrote the diagnosis in two places in the record but didn't write that same thing a third time under the exam.
If the documentation is truly deficient and can't be coded, then the correct remedy is to query the provider for a clarifying amendment, not to make their work 'non-billable'. Personally, I wouldn't trouble the provider with something as trivial as this because providers have a lot more important things to do than changing medical records around because of rules that coders come up with that don't really exist. Perhaps just jot it down as a recommendation or an FYI to give them the next time you have a documentation improvement session with them. Coding efforts should be focused on larger issues that impact revenue or put the practice at risk, not on minor technicalities or imperfections in individual notes.