This bothers me, what the heck did they use? If they used a gasket then at most a little high tack is all that is needed to hold it in place for installation and once its bolted down it needs no time to dry.
I have a sickening feeling these guys may have used RTV either on the old gasket or in place of a gasket god forbid. This engine uses an almost $50 cover gasket that are not readily available aftermarket, it seems to be a dealer item.
Edit: If they did either of these things they would deserve more than an earful.
This is a very good point and the OP should directly look into this