There are practically important algorithms like this. There are three linear-time algorithms for constructing a suffix array, but all of them have rather large constant factors. Packrat parsing is linear in the size of the input string, but can easily execute more than 100 instructions per byte. And there are numerous theoretically asymptotically superior algorithms whose constant factors are too high for them to be useful at all, the so-called "galactic algorithms", https://en.m.wikipedia.org/wiki/Galactic_algorithm.

There is nothing in the article suggesting that this is such a case, however.