Their mistake was making a note to take care of it at the end of the year. The note should live included instructions to check it twice. Had I not checked my stub I’d be out $600 in double dipping for taxes. If I was careless that bonus money would have been included twice for gross income and the money for taxes lost in tracking.
Checking your stubs is not just for those living p2p. It is part of sound financial accounting. Would you run your accounts payable the same way? Anytime there is a chance for human error you’d be foolish not to check.