These were seemingly all the weekend charters run from Heathrow with spare time on the short haul fleet.
You might (sort of) understand if BA had initially said they did not do compensation for charters, although that is clearly wrong as otherwise passengers on holiday charters would not be covered. But to say it was the old catch-all, "due to operational circumstances outside our control" seems to show that this old chestnut is just trotted out whenever convenient, and when it is nothing of the sort.
'You talk about it as cost-cutting, I talk about it as efficiency': BA boss Willie Walsh defends airline
One of the "efficiencies" is the long term trend with capacity at Heathrow. Now with restricted slots you might think there would be a trend to increase aircraft size to increase revenue per slot. But steadily BA is doing the reverse, repeatedly ordering aircraft, describing them as new and large, but in fact replacing even larger aircraft. Thus the recent 787-9, which was certainly portrayed as a 767 replacement, is principally replacing the 777 on many routes. And in fact those 777 routes, not that many years ago, quite likely had 747s. Meanwhile the 767 routes in Europe have been steadily replaced by the A321, and what the A321 used to do is replaced by the A320. ...etc ...
This may suit this year's Spanish shareholders and bonus collectors, but it is a real Selling Off The Silver of the airline, just squeezing it down to an ever greater margin but smaller number of passengers. Competitors, of course, find it difficult or impossible to get Heathrow slots.
Isn't this just the sort of area that a government regulator, concerned with national economic policy, should look at ?