I stay in so many different hotels, so I always ensure I get a full printout of all charges and also a full printout of the paid amount, all on one statement, so it can be seen that all charges have been paid at checking out. If they want to check the mini-bar prior to me checking out that is up to them. If I stayed in that hotel then I would specifically ask for them to check the mini-bar and write on the statement that nothing was used from the mini-bar, along with the signature, name and date.