this person never trains but teaches the lion share of the classes...
the laziest Aikidoka, some one who has been honest about having no love for the art who has admitted to just being in it to appease their spouse....some one who's been verbally abusive, arrogant, and over-all have ego trips at junior's expenses.
some of us have had surgeries to cope with training accidents.
If I didn't love Aikido I would leave the school, but there is no where else to train.
Based on the limited info you provided (which I selectively cut/paste above), the place sounds toxic to me. "Looking the other way" because you feel the person has some kind of monopoly is a risky thing to your well being and that of others behind you. I suggest you evaluate other options with a creative and open mind - including other martial arts.