I should have paid more attention, lol. In my defense, the top of the saucer looks like sloped top infil on layers.

In any case, I would have to wonder if there isn’t some contamination that weaken that particular layer. While much lower than FDM, there are still internal forces that can build up and lead to cracking around weakened points. it could have just had some weirdness in the layer not sticking right acting as a focus for those stresses.

I’m guessing it’s related to the corrupt file containing bad instructions, resulting in that layer having weaker-than-it-should adhession. the internal stresses then led to the crack happening (and expanding) as the print continued.