Randomly pulling "180 days" out of the PayPal terms of service as it applies to account closures and suggesting that somehow it applies to payment reversals seems to me misguided or maybe even a bit disingenuous.
No..... 180 days is how long a PayPal user has, merchant or otherwise, to issue a chargeback. It's not a random number. So far my feedback and experience has been positive. I will let others know within or at 180 days after my transaction if that changes.