What on Earth are you talking about? There's nothing "iamverysmart" about the blogpost at all. The guy literally cites an example where the code broke in production, it isn't an esoteric hairsplitting point at all.
They tried to implement a standard algorithm themselves and failed. Doesn't mean that almost all binary searches are wrong. C++ standard library had a correct implemented binary search with more flexible signature when this article was written, they could just have used that one instead.