Headsethair you feel like an old friend! BA do indeed allocate a lot of the stands for T1, but by no means all. As far as I am aware the terminal controllers have not walked off the job, the only problem is that our stranded aircraft may be blocking some of the stands. I don't think the disruption to other operators will be massive. In this instance I don't think there's very much BAA could do even if they wanted do. Far be it from me to defend BAA, they simply don't have legions of check-in staff and and baggage handlers trained in BA procedures to simply step in and take over should our staff walk out. Perhaps the best they could do would be to help set up some sort of hotel help desk to accommodate stranded passengers then bill BA. I don't think I've seen the thread about T4/T1 congestion, where is it? I'd certainly be surprised if LGW flights had been sent to LHR as there'd still be nobody to handle them. In summary, whilst I'm no fan of BAA I'm not sure that they could do much to help once our ground staff decided to screw us all and walk off the job.
A and C I can assure you the baggage handlers walk off the job with alarming regularity. Third time in the last 12 months. No surprises to see their militant hand in this debacle.