Mor,
There doesn't seem to be any justification, at least from this canon, for a complete break (as I perceive groups like ROAC and the GOC have done), but only for "walling off". How, then, can breaking away completely (I am avoiding the use of the word "schism" because of a connotation I do not want to imply in my question) before a conciliar/synodal judgement is rendered be justified?
Re-reading the canon in question, the erring bishops are called "pseudo-bishops" - I don't see how one can have any communion with this (how does Orthodoxy have communion with heterodoxy? Bishops with pseudo-bishops?)
Just as a concilliar declaration does not need to occur for anyone to apostacize, neither does such need to take place for heirarchs to apostacize. Such, sadly, is seen in what they confess and teach, or remain in fraternity/obedience towards.
Seraphim