BA certainly did have an incentive that helped push through the settlement - it was its public listing. Maggie Thatcher personally intervened with Ronnie Reagan to prevent an anti-trust lawsuit from going through that would have resulted in considerably higher damages if proven. You'll recall that as part of the settlement, the carriers involved had to issue refund vouchers to all their passengers for a relatively nominal sum for each transatlantic flight they had taken between certain dates - I can't recall offhand what those dates were, perhaps someone else can?
I met Harold Bamberg a couple of times, including visiting him at home in Sunningdale. Fascinating bloke!