Agrapart label help

I purchased some Agrapart Blanc de Blanc Terroirs, and I am trying to decipher the lot information. It says: “Lot October 2012” and immediately after it say “May 2015.” I’m guessing one of the dates is the disgorgement date, but I’m not sure why there are two dates. Can anyone tell me what this means?

To my recollection, the first date (above) is the bottled date (Oct 2012) and the second date (below) the disgorgement (May 2015).