The big difference between the two scenarios, SP, is that the Lindsey workers are both specialised AND demonstrating solidarity.
This does not apply to LHR cabin crew. There is a large and willing cadre of staff at LGW trained to exactly the same standards as those at LHR MORE than willing to come round the M25 and do the work, plus a huge number of crc checked former temporary contract staff desperate to have a more permanent job with BA.
With minimum crewing (and the inevitable strike breakers) there are plenty of people to keep the show on the road should BASSA push the self destruct button. Talk is cheap, and nowhere is it cheaper than on internet forums, but actions are much, much more expensive. The rest of BA can see that (the wholely unrepresentative) BASSA are willing to risk the future of the entire company through their intransigence and inability to handle change. There will be scant support for any industrial action from other departments, and a lot less within the cc community than you think. Time will tell.