McLuhan research is full of inaccuracies and ridiculous claims.  Even such a thoughtful writer as Graeme Patterson (1934-1993) blithely made observations which were simply ludicrous.  Here he is in History and Communications (1990):

Outside of his introductions to Innis’s work, [McLuhan] took no interest in biases of space and time. (122)

 A good argument could be made that McLuhan never thought about anything else.