Misapprehension 10: We must reach 100% MC/DC, because then our software is error-free

It is correct, that / (MC/DC) is one of the more sophisticated coverage measures, which for instance needs to be provided for products on level A (the most safety-critical level) according to DO-178B. However, to reach 100% MC/DC you usually need more test cases (i.e. test effort) than for less demanding measures, e.g. branch coverage. Is this higher testing effort worthwhile? If you have a huge budget for testing, you certainly should consider aiming for 100% MC/DC. Unfortunately, in reality, the budget for testing is often limited. Therefore, you should ask yourself, if you shouldn’t invest the additional effort required to reach 100% MC/DC in other kinds of tests, e.g. in reviews, mutation testing, or static analysis. The rationale for this is that even 100% MC/DC does not guarantee error-free code, because e.g. MC/DC is insensitive against errors in calculations, like any other coverage measure.
However, the author must admit, that he knows from a case in real life, where unit testing was already finished with 100% branch coverage reached. Then, the requirement for 100% MC/DC was raised, which required additional test cases, which actually revealed a programming error. This error would have gone undetected without the objective for 100% MC/DC.