Embolism?
Chris - I was just trying to make sense of the previous posts, and yes, it is pretty unlikely/unprecedented, but same fuel, same temperatures, and very nearly identical tanks (one hydraulic heat exchanger versus two) means that the independence may not be what it seems. As has been pointed out earlier, the fact that there was a small differnece in the reactions of the two engines means that the electronic explanations may be less likely than the 'mechanical' ones. In the end I'm as baffled as everyone else, this is a fascinating puzzle but it feels we may be zeroing in on the answer.