According a direct quote by him on CBSsports.com
"I'm leaving. I'm headed to Toronto now. I enjoyed my time at Pittsburgh, I love Coach (Jamie) Dixon, had no problems with the staff and the players. It just wasn't the right fit for me."
Jamie Dixon: “Khem has decided to leave the team for personal reasons. We thank Khem for his contribution to our program over the last semester and wish him great success in the future.”