Yes Simon, we did have a figure 8 with a overhand knot on top, but it was dragged straight trough the traveller. Needless to say that this knot is significantly larger now..
The amazing thing about our two incidents was that it was not heavy weather, and the jibes was not violent at all. Once the traveller stop broke and the knot was sucked trough, the second time one of the bolts for the mainsheet that goes trough the car broke and the whole thing was wrenched off. All the other T guys was properly impressed each time, as this sort of things always happen during regattas of course (the olympic guys had not seen either thing happen before)..