The abuse was multi-pronged. It wasn't just that Taylor was a popular player with the public and the media. It wasn't just that they had performed so abysmally in the South African tests immediately after the captaincy changeover. It was also the ex-players in Taylor's corner who were stoking the fires on his behalf that bothered McCullum most.
It didn't help, McCullum wrote, that their best batsman wasn't in South Africa.
"It would have been great if Ross had been able to come out and say, 'Look, I lost my job but I'm committed to scoring runs and performing for New Zealand and being part of this team'," he writes.
"But the people surrounding him at that time were never going to let him do that. Martin Crowe told the media he'd burnt his New Zealand blazer because of his disgust at the way Ross had been treated.
"If Ross had different people around him he might have been able to get a bit more perspective on what happened. He wasn't the first captain to lose his position due to the team performance and he won't be the last. If you looked at it objectively, his decision not to come on the South African tour was quite bizarre, and really only explicable in terms of people fuelling his emotions behind the scenes."
New Zealand returned from South Africa and played a galvanising home series against England, although McCullum points to issues "reintegrating" Taylor into the side.
Things turned to custard away from home, with the team, and McCullum in particular, struggling badly in England, Bangladesh and Sri Lanka. Allied to that he'd called the lawyers on former international John Parker, whose distribution of a long and tortuous document alleging, among other things, that McCullum and his backers had conspired to have Taylor removed as captain.
"My personal stats were abysmal. I knew that if I couldn't turn [it] around quickly, I'd be next for the chop - both in terms of captaincy and holding my place in the batting line-up. And deservedly so."
The West Indies were next up. McCullum scored a ton, Taylor a double-ton and, although rain ruined the first test, they started winning.
The worst times - until the Chris Cairns trial at least - were over. Thoughts of retirement were, temporarily, shelved.