There was a thread on the "LVA" forum about Plaza. One poster stated that he had heard that the reason that Plaza switched some of their Pitch Double Deck Tables to Double Deck shoes was because of dealer "mistakes" that cost the casino $100,000 in a one week period of time. Actually, he said it was the Las Vegas Club that invoked that change but Plaza is owned by the same people so they made the change also. As far as I recall, the LVC and Plaza use Peekers (the mirored optical device) for checking the hole card for Ace or Face.
Because of the Peekers, I have to assume that the dealers causing the problems were flashing their second card as they dealt it or were flashing it as they tucked it under or when they flipped the up-card.
The Plaza doesn't have a huge turnover in dealers. I've been playing against the same two dealers for the past year out there and they've been there much longer. I have to assume that it was dealers at LVC that caused the concern if new dealers were guilty of allowing first basing or front loading.
But for whatever reason, I am glad they have gone to the double deck shoes. When they did this, they also switched the game to a face up game! All cards are exposed on the deal except for the dealer's hole card.