Indeed, the fog has been playing hit-and-run the last couple days. Down where I am (not Basel, but the Breitling Connie flies by enough that I recognize the sound of those supercharged pistons before I see the plane), this morning everything was clear, save the fog bank eating half the town. Yesterday evening, it rolled in fast, people stopping to take pictures fast.

Listening to the BA pilot reporting to the tower that the plane passed over their flight deck at right angles (way off the runway centre line) seems to say you were a very lucky boy Buffalox!

"passed over thieir flight deck at right angles..."? Could that mean "90 degrees of bank"?

If the BA was waiting at the Cat3 HP it would normally have been holding at right angles to the r/w and so the a/c on approach would appear to pass them at right angles; nothing to do with the attitude of the a/c.