Me too. I'd hope the pilots were aware their weight calculations were awry, and they were well over a tonne light before they left the gate.

If that reasoning holds, the decision on whether or not to fly to Singapore with empty water tanks must have taken place while the plane was on the ground at Heathrow. Siri is silent on how long it takes to fill those tanks: but if the flight could wait for crew duvets to be delivered, maybe the water-fill operation would have sent crew hours over the line or breached the airport's curfew.

Let's hope that sanctioning the omission of an expensive, but what appears to be a non-essential, element of onboard equipment doesn't excite BA's bean counters too much.