1) It wasn't the biggest fee ever in British football
2) You don't know they wouldn't have sold for less if that's all that was offered.
3) It's nothing like that analogy at all
He had no choice about the club selling Carroll. However he made a big song and dance when he joined about being given a guarantee that Carroll would not be sold. If he had any integrity he should have made a stand and threatened to quit if the player was sold (unless he was replaced immediately with a striker he considered to be better and was given a guarantee that all the remaining money would be put back into in the transfer budget).
As it was we went into the second half of the season where we were doing okay, but were by no means safe from relegation with 1 striker who was proven to be adequate at this level, but who is very injury prone, 1 striker who was proven to be inadequate at this level, and 2 strikers who were completely unproven at this level. Newly promoted clubs are notorious for having a good start and nosediving in the second half of the season, the sale of Carroll with no replacement could easily have triggered that decline. It's risky management to the point of negligence from an owner who has supposedly learned from his mistakes, but the manager being the senior man in charge of the footballing side of the club should be doing everything in his power to try to stop it or at least try and compensate for the loss of the player with an immediate replacement, permanent or otherwise.
For all we know he may have.