DH should not still be the Branch Secretary. It is clear in the rule book that you need to be employed as cabin crew in BA to even be a member let alone Secretary.
I read somewhere that as BA was in dispute when DH was sacked, his status as Branch Secretary is "held" until the dispute is over. Hence it is in his interests to keep this dispute going as long as possible as BASSA will keep paying his salary. Once it is over, he is effectively out of his BASSA job (as he is no longer BA and unable to represent BA crew according to BASSA rules).
Call me ironic, but I see him as prolonging this dispute for his own monetary gains and not the welfare of the crew.