I would have thought if Hunt is adamant there is no black hole that he would support the OBR in vindicating him.
He only seeks to hide this because there must be a black hole.
The only other explanation is that the OBR has taken sides against him, but that would seem unlikely in such a short time since Labour took office.
More likely the conservatives were suppressing the OBR when in office.
He got caught by his own trap of lowering NI twice to create this black hole for labour to sort. Once he set that trap, as amateur hour as it is, he was committed to this path.
He's the sort of person who gets both his legs stuck in the same trouser leg.