I have no information, but I just love the irony...
Knorr did not want Covington as his Vice-President. Rutherford insisted on his death bed that Covington be appointed. Knorr was poorly educated and Covington considered him ignorant.
Rutherford wrested control of the organization away from Russell's chosen successors after Russell's death.
It is quite fitting that Knorr similarly screwed Rutherford when he died.