A research paper from Google in 2006 noted that "almost all" binary search (and merge sort) implementations contain a bug (and had for decades), so 90% seems impressive in the face of that.
https://research.google/blog/extra-extra-read-all-about-it-n...
The bug in that paper is actually the very buffer overflow bug I was referring to. Given that Jon himself made that error in the "definitive" implementation, it seems unlikely that he would have spotted it in the 10% of implementations he considered correct. Under Google's stricter criteria it seems likely to me that not a single person got the search implementation truly correct enough.
In Javascript that Google "bug" only occurs if an array has more than 4503599627370495 items. You may run into memory issues before running into that bug.