According to the Reddit thread he could have possibly been using a beta BIOS, which could have caused the issue.
Also looking at the image he posted on Reddit in its full zoom I'm not seeing any "debris". It's slightly fuzzy but the CPU pads appear to be scorched or missing, while the pins in the socket appear to be bent sideways or melted, as you would expect if it were an electrical short, and combined with JPEG compression, camera flash, and phone camera processing it appears to be slightly different colors, and could easily be the CPU pads having been fused to the socket pins, that would be the shape of the pads.
My money would be on a beta BIOS overvolt, I'm not so sure a mis-manufactured socket pin causing an electric arc would have lasted weeks, as I can't see pins slowly bending over time towards each other until they touched.