In February 2018 Hillier filed a formal complaint against former Ontario PC Leader and MPP Patrick Brown during the leadership race which was caused as a result of Brown resigning as leader. "I've known Patrick Brown to lie just about every time he opens his mouth" Hillier told reporters, he "engaged in dirty and crooked politics". "He purposely and willfully lied to the people of Ontario." An investigation found no evidence to support Hillier's allegations that Brown failed to disclose gifts of travel. Brown publicly responded calling Hillier's allegations “garbage,” and “fabricated”.