I'm sure there have been failed attempts in the past, too...I don't care to sort through dailies for 4 hours, but if you do, then be my guest. Bottom line is that it didn't actually shift, nor is it expected to do so for several more years. Off the top of my head, though I'm sure you will examine the dailies and find some inconsistency...but February 2000 featured an uncharacteristically +PNA during a La Nina, and then of course we had the 2000-2001 season that must have had everyone convinced that the Pacific had flipped....yet 2001-2002 happened.
Bottom line is we need to see where we are in the early 2030s.