Last and Final

Have you been in an airport recently? I have, and I keep hearing airline employees over the P.A. system saying something that is driving me crazy. They say: "Attention passengers of AirDope Flight Number 1254, this is your last and final boarding call." And within 90 seconds, the same person repeats the message. There are two GrammarSnot issues here:

1. How can something be last AND final? I don't believe this is possible, grammatically, or metaphysically.

2. Airline employees are liars. If they are really making the LAST boarding call, then, by, you know, definition, you can't make another LAST boarding call.

This is not my last posting.
Cicero