Timegrapher claim

[p_mcgee]

I bought a Grand Seiko watch online in "like-new" condition that I'd been eyeing for a long time. Seemed like a good deal, seller was a newbie but had a lot of eBay feedback so I decided to buy with PayPal G&S with buyer protection. I receive the watch, looks nice but almost immediately started gaining time against the atomic clock (nis site). The next day it had gained between 15 and 20 seconds. So, I notified the guy that his watch probably needed to be serviced & I was sending it back. I'm not sure if the warranty was any good & if there was going to be a long delay sending the watch to Japan for service. The response was pretty bad, seller called me a liar several times, said he was coming over to my house. Then 2 days later (before I blocked him) sends me a chat message calling me more names, but with a picture of the watch on a timegrapher, claiming its running withing 1 second per day. I figured it was some kind of scam but is it typical that timegrapher results would be so far off?