O'Neil said: "I think Harry probably made the right decision to stay where he is. I expected him to stay at Portsmouth because he's done such a fantastic job and seems to be building something really good there.
"He is really loved on the south coast and I didn't think he would leave halfway through a job.
"Pompey are going to go on to bigger things, especially with the signing of Jermain Defoe. I always got on great with Harry and when I left it was just of question of him deciding they wanted to take the money and spend it elsewhere. There were no hard feelings."