I have never seen two people try to play a game of technicalities so zealously. However, to be really technical, here is my take.
DNP showed confusion over the end time after he had made the $1,200 bid and before he retracted it. That was at 5:08 in post 11.
OP comes in after 6pm and clarifies that it will be based on the forum clock but as that had not been clear, he places the end at an exact time and to be fair extended to 7pm as it was already past 6pm. When DNP retracted his bid, he essentially broke the contract because his bid was made even when he was unsure of the end time. Again, that was at 5:08pm. To go back and change it left the OP with an auction process based on a legitimate and binding bid by DNF. When that changed, so to did the auction.
If you want to continue to insist that the $50 bid was the last one, you would be wrong again because of the time stamps on the posts. The absolute last time-stamped post by the OP was his edit of the original post which was at 6:17pm and that post set the time the auction was over at 7pm. The one that said it was to end at 6:59pm has a time stamp of 6:16pm. Again, his last time stamped post says 7pm end time. So, no matter how you look at it, the $50 bid would not win as there was a higher one time stamped at 7pm and it doesn't matter because DNF voided the auction when he retracted his binding bid.
DNP is taking shots at the OP when it could just as easily be argued that he and cadillac880 could be working together on this. The point is that these things are often not so clear and to try to stick it to the OP after all these posts have been edited is ridiculous.