There was no mention of a recent audit. They extensively interviewed a guy who was hired (tapped on the shoulder) to be their auditor but he was made redundant in 88 also with no obvious reason.
So that idea was not debunked at all.
At some stage in the 70's politicians kicked up a stink and that was the last time the public i.e a few politicians and journalists were allowed in to see the gold.
If anything the programme aroused a lot of suspicion due to the impenetrable secrecy but emphasized how safe the gold was due to it being right next to a huge military camp, indeed it spent the last 1/3rd of the programme examining the history of the tank and the amazing training environment in the adjacent Camp Knox. It was impressive too.

But that doesnt make me believe the gold is safe