Former England coach Stuart Lancaster expressed surprise over the criticism thrown at him by Rugby Football Union's former director of professional rugby Rob Andrew.
Andrew in his book The Game of My Life: Battling for England in the Professional Era, published in the Telegraph described Lancaster as "control freak" and "obsessive" and further slammed the 47-year-old's selection policies including fast-tracking rugby league convert Sam Burgess in the England squad.
England with defeats to Wales and Australia had to exit from the tournament in the first round which also marked an end to Lancaster's reign and he was replaced by Eddie Jones.
"Everybody's entitled to an opinion, Rob has given his and that's his right," said Lancaster.
"You learn a lot about yourself as a national team coach and you learn a lot about other people as well. I didn't see this coming, I wasn't aware that anything was being written.
"When you take the responsibility, you're accountable when it doesn't go well. I think I did that from the start and I will continue to do that.
"I coached over 50 international games which I think puts me second-most or around there. You go through good times, you have great wins and great moments.
"You go through tough times as well. I've got my thoughts and I'll keep them to myself for the time being. I don't think it will do anyone any good by going back all over that now.
"It's not for me to comment on whether it's the wrong thing to do.
"I was unaware it was coming up. People are motivated in different ways. He was in the (RFU) organisation and I joined the organisation in my original role with the academy in 2007. We worked alongside each other, is the best way to describe it."
Lancaster was later appointed as an assistant coach of Pro 14 club Leinster under head coach Leo Cullen.