According to (many) BA FEs I've spoken to, it's extremely unlikely the tanks would have been overfilled on any BA departure, therefore there'd be some air space above the fuel to get compressed and absorb the hydraulic shock of the base of the tank being clouted by a piece of tyre, therefore no torrent of fuel pouring out the bottom of the wing, therefore a controllable 'incident' at worst, rather than a total disaster.
And that's ignoring the other AF factors (spacer, downwind, overweight, no.2, etc).
Not conclusive of course, but it is food for thought.