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 Bill Ackman, an activist investor, to become the president and CEO of CPR if Ackman won a proxy battle against the company's board in spring 2012. This would lead to Fred Green's removal from his position as president and CEO.