In fall 2011, Harrison was approached by the hedge fund Pershing Square Capital Management led by activist investor Bill Ackman, who was undertaking a proxy battle with the board of directors of CPR. Ackman had offered at that time to appoint Harrison as president and chief executive officer of CPR should his proxy battle in spring 2012 be successful, which would necessarily result in the termination of Fred Green as president and CEO.
In fall 2011, Harrison was approached by Pershing Square Capital Management, led by Bill Ackman, who was engaged in a proxy battle with CPR's board of directors. The outcome of the proxy fight would determine Harrison's appointment as president and CEO of CPR, replacing Fred Green.