There's a bit of mis-information here.
First, while credit card companies and banks can chose to honor disputes of any age, your rights under the FCBA protect you for only 60 days -- and the FCBA doesn't apply to debit cards at all.
My tip -- that you should never use a debit card and with credit cards you should dispute charges before paying the bill -- is correct in spirit but not in the letter of the way I worded it, so mea culpa on technicalities but the point is correct. The FCBA only grants you 60 days to dispute a transaction (after the statement cut, not the transaction itself).
Also, CC disputes have some consequences. Companies aggregate & share lists of customers that have charge-backed. Finding yourself on the list can see you turned-away from legitimate, good businesses that have to protect themselves against dispute-prone customers.