What I'm saying is that there might have been more general contamination in areas that weren't required to be clean. They might not even have searched as there

What I'm saying is that there might have been more general contamination in areas that weren't required to be clean. They might not even have searched as there's no expectation of sterility of the outside of the container. From a practical standpoint we normally do not care if our hands touch an apparently clean container and then have contact with food but that is a possible route of contamination. A clean, dry container is very unlikely to harbor a pathogen that poses a threat so we do not normally act as if it's a contaminated surface--but that doesn't mean it's impossible for it to pose a hazard.