From the horses mouth on part 2 of his guest appearance on John Parkin's podcast Under The Cosh.
We activated a £750,000 release clause in his contract after his drugs ban was up in 2010. He mentions it at about 18:30 of the video below and at about 25 minutes he mentions we offered him "more money, a lot more money" than QPR did but he wanted to join Warnock again. Our recruitment that year was a shambles.
We ended up with David James on that disgraceful wage so... Maybe Paddy would've been better!