RR, just a suggestion re: the "short" at the connector strap. Look closely and see if you are not tempted to look at the deficit as "cut" by a gas jet, instead of a simple "fusion" due to heat of current. The battery case is aligned with the triangular "cut", and the metal has characteristics of a torch cut, complete with "beads" of molten metal along the very linear edges..... Is it completely severed?
Just a suggestion: Since there are so many pictures circulating whose captions even mistake which of the two batteries is shown, could you add a link to a picture of the area you are discussing?
If you are talking about the one I am thinking of, with the attachment nut sitting loose on top of the cell, a large part of the connector appears to be totally missing, not just cut. That is more consistent with a high amperage vaporization of the metal than with a gas jet cut, although
both events may have occurred as slightly different times.