From Jericho's new book:
While on a plane, McMahon made a snide remark to Kingston, saying, “maybe one day you’ll get over.” Jericho wrote about Kingston looking visibly infuriated, and catching up with Kingston upon departing the plane. Jericho told Kingston to return to McMahon, and challenge him to a fight. At first, Kingston seemed to think everything was one big rib. Though, with Jericho having built a close relationship to McMahon, he knew McMahon, a man with great seriousness, was not joking.
Kingston would heed Jericho’s advice, asking McMahon if he had a problem with him. The two would throw verbal jabs each other’s way, eventually leading to a physical collision. It began when, out of nowhere, McMahon attempted a double leg takedown of Kingston. The two then proceeded to wrestle around for a bit.