This other eBayer had bid each opposing bidder up to their maximum and in some cases even cancelled his/her bid once it was in a winning position, leaving the opposing bidder on their maximum bid.
Looking at this bidder's history, he/she seemed to only ever bid on this particular seller's items, a sure sign that there was more going on than met the eye.
This technique is known as shill bidding and is against eBay rules - indeed it is classed as fraud.
If you are found to be doing this it is very probable that your eBay account will be suspended.
An old work colleague used to use this particular method to get higher prices. He would bid up his auctions until he went over the previous high bidder's price.
When this was achieved he then cancelled his last bid, leaving the high bidder at their maximum price. His explanation was that he didn't want to lose money on any of his auctions and that he wouldn't sell them for less than they were worth.
Suggesting he used a reserve instead didn't work as he didn't want to have to put reserves on any of his auctions as they put potential bidders off. And you are also charged more by ebay for this service.