and I think three respected posters had mostly agreed with the possibility of such a result in their respective simulations
Actually, the sims all hinted to the possibility of exactly what happened.
I never saw golfho's "work", but the other 2 had decent numbers showing how the control arm should be progressing. But the result of that left the Bavi arm with very few events, far fewer than what one might rationally expect.
So at that point we knew the control arm was doing exceptionally well. It still could have played out OK (with Bavi besting an outperforming control). But certainly what happened was in play.