About a year ago my AD called me and said he had a 5131 enroute and would I like to apply. He told me there was only one watch for his three locations. I obviously applied. About two weeks later I was told that the 5131 was given to a customer at one of the other stores. My AD told me it was Patek's decision. I was dissappointed but life goes on.
A few weeks ago he called me to tell me my 5131 had arrived!
I believe the AD gets the alotment for the watch and then submits the application to Patek for the final decision.