It is possible that your winning bidder saw your high bid and placed a new bid in 13 seconds, but I think it is more likely that he was using a double bid technique. He either deliberately placed two successive bids close together near auction end, or used a manual bid to complement an automated bid.
He may have used a double bid because he knew that there was a nibbler in the auction. (Double bids are quite effective against nibblers.)
The $45.00 first bid does not necessarily indicate that his final bid was a whole dollar amount.