"I do feel the way Peter handled things towards the end of my time at Celtic was out of order," said Miller. "He said things, perhaps to scare me into moving, which didn't have to be said.
"Some of them were quite insulting. I just feel there was no need to go down that road and he could have handled things in a different way.
"He didn't have to get personal, he didn't have to throw the toys out of the pram because he wasn't getting his own way.
"At the end of the day, it could have been sorted out in a much more amicable manner.
"Instead he tried to make my decision for me and force me out because it suited him."