I do believe sellers can pull their listings but with a price. That's why if you take a look at "completed listings" and click on "lowest first" there will be a lot of $0.99 free shipping auctions with 0 bids.
June 30th was the day before the big market takedown. Maybe they sensed it was coming and decided to wait until silver was headed up again to optimize their chances of getting a better final bid?
I think it would say seller ended listing early if he pulled it. It shows in his completed listings as sold at 99 cents. Somebody looks to have gotten lucky (the risk of one day auctions) and it sure wasn't the seller!