I wondered whether he has substantial shareholdings. If it were large enough, I personally would consider resigning which would allow me to sell shares without having to disclose to the market, whereas he cannot do this while a director. If he knows he is a goner anyway, then why not sell the shares - something he can't do while a director.
This musing I had in the shower seems a bit far fetched to me, but thought I'd put it out there.
GS