Re: inspecting the can opener....
Yes, they check that, as well as the temperatures of any area where food is stored, be it hot storage (steam table, hot box, proofing box, etc.), or cold storage (refrigerator, fridge/prep table, sandwich board, salad board, walk-in refrigerator, freezers, walk-in freezers, etc. ALL of the fridge's where I work have thermometers in them, and believe me, I check them constantly.
Inspectors also check to make sure that proper handwashing procedures are followed, sinks are clean, gaskets on refrigerator doors are clean and in good repair (this is a big one), etc.
If I were an inspector, the very first thing I would do, in any restaurant, is look to see if they have a stand mixer (think Kitchenaid 5 qt, only much bigger). I'd make a beeline for that and look up under where the paddle or whisk is attached. That area doesn't always get cleaned good, and the dried on food can flake off into the item being prepared.
I'm the pantry supervisor at my country club, and I have to pay VERY close attention to cleanliness and sanitation, as many of the items we fix are ready-to-eat and/or raw items, that do NOT get cooked. Cross-contamination in ready-to-eat foods is a big problem causer.