His position had become untennable and, as he points out himself, the fact he didn't do this earlier undermined the point in the referee strike. For this he can only blame himself.
However, I have sympathy over the way the circumstances escalated from that incident to the point we are now at. Frankly, I would find it nigh-on impossible to work with some fucking neanderthal like Lennon continually being confrontational, aggressive and critically assessing a job which I imagine he has absolutely no understanding of.