Let's let the man himself explain why he did so: "They only wanted to sign me up until January. The contract they were offering me was nothing special. Scottish clubs don't take risks and they just offer very short-term contracts.
"It's all well and good to sign up until January, but what would I do if I got injured just before then? I had that sort of misadventure at Manchester City. I signed for six months with the option of four further seasons, but I got injured in December. I did not want to make the same mistake again, because I am 30 now."
Fair enough, he didn't want to take the risk. So why agree the deal with Saints and then turn it down? Surely the deal he originally agreed would only have been until the end of December?
What does the future hold for Karim? Well... "A couple of other Scottish clubs want to give me a trial, but they are in the First Division, so I prefer to bide my time and wait.