Hankey was drawn in Group B of the 2012 Grand Slam of Darts with Michael van Gerwen, Robert Thornton and Steve Beaton. He was whitewashed 0–5 by Thornton but defeated Beaton 5–3 to stay alive in the group. However, requiring a 5–0 or 5–1 victory over Van Gerwen in his last game to have a chance of progressing, Hankey visibly struggled with a three-dart average of 59, missing five successive shots at a single in the first leg (including two that missed the board completely) to set up a double. Hankey was then seen rubbing his left eye repeatedly and losing his balance, and Van Gerwen eventually won the match 5–0 with a 90 average. Two days later it was revealed that Hankey had suffered a 'stroke', had very high cholesterol and diabetes and needed six to eight weeks' rest, which ruled him out of the qualifier for the 2013 World Championship.