BA uses smoke and mirrors in order to paint a more rosie picture than is real – example Flights cancelled only count those cancelled within 24 hours of flight. It is usual to merge/transfer flights in advance in normal ops then the flight is no deamed cancelled. Hence T5 resembling a ghost town whilst BA asserts 80-90% of its sceduled flights went out.
Also when counting people who take industrial action, as the majority of crew are either en-route, downline, on rest, working 66% or 50% rosters they are not in a position to take IA at a point in time. So BA reporting only 1,500 out of 10,000 crew took action is disengenuous as only 2,000 would have been scheduled to take a flight out on the strike day and thus been in a position to take IA.