After losing the Ashes in Perth, the England players held a meeting among themselves, without the presence of team management, to try and map out a way forward. It has since emerged that Pietersen was among the most forthright at the meeting and the comments made their way back to Andy Flower.
Few confirmed facts are known about the reasons behind Pietersen's sacking due to confidentially clauses on both sides which will expire in October. It is believed that there was not one single incident that led Paul Downton, the managing director of England cricket, into the decision to end Pietersen's international career, but instead a number of smaller issues that built up to make the ECB decide that England's future was better off without him.
Tremlett, who remains a team-mate of Pietersen's at Surrey, said it was a "shame" that the batsman would no longer appear in England colours and hoped he would prove the decision wrong.
"I don't think he did anything wrong apart from voice his opinion," Tremlett said. "We had some honest chats and Kevin is a pretty honest character.
"When times are tough and you're in a squad like that, sometimes people find it hard to express themselves but Kevin isn't one of those people. He's not afraid to say what's going on or to tell it how it is.
"I don't know whether that is why Kevin has been shot down but it is a shame that he isn't able to play for England anymore… hopefully he goes out, scores lots of runs and proves England wrong."
Pietersen will be playing for a Surrey side now coached by his mentor Graham Ford, who believes the county's young batsmen will benefit hugely from playing alongside him.
"When they do get an opportunity to bat with him it will be a masterclass and a great chance to learn," he said.
"He's a good enough player to prove a point in any format. He'll certainly entertain and it will be great for the fans to come down and have a look at him and see just how good he is.
"Unfortunately he's got to move on from international cricket. The news was surprising. I don't really know what went on, but I have known Kevin for a long time and I've always found him to be a very positive individual and I'm sure he's going to be extremely positive in our dressing room.''
Pietersen's sacking was just one of the fall-outs of a horrific Australia tour for England which also brought the end of Flower's time as head coach, included Graeme Swann's mid-series retirement, saw Jonathan Trott return home after the first Test and had Steven Finn's form disappear to such an extent that he could not be selected.
Tremlett, who played the opening Test in Brisbane before carrying drinks for the rest of the series, was just glad when it all ended.
"The mood changed after the third Test," Tremlett said. "Communication wasn't as good as it should have been. It can be tough when you are losing like that and people are panicking; the team was changing all the time.
"Jonathan Trott and Graeme Swann went home before the tour end, so it was the most disjointed tour I've been on. It was a bit of a disaster and I was quite thankful to leave at the end of it."