Gobbleydegook: You hit on an area that may not have been clarified in the book.
The initial industrial action,IIRC, took the form of a type of contract compliance ( WOE campaign - withdrawal of enthusiasm ) The AOA then instigated, perhaps under the influence of advice given by ALPA, several days of "mass sick-outs". This was never admitted by the AOA as being industrial action - the official line was "our members are too stressed to come to work".
The logic being that you can not be fired whilst on sick leave.
This in my opinion was a grave error of strategy which precipitated the backlash from DT. A dirty response to underhand, unacknowledged tactics.