The essay is more concerned with the definition of “technology” than the definition of “science fiction”. It merely points out that distinguishing between hard and soft sci-fi by the presence of technology is folly, since even Bronze Age technology is still technology.

Hatchet has technology - the titular hatchet, along with the airplane that crashed and the various items the protagonist collects at the end. But the presence of technology in the work does not determine if it is science fiction or not.

This is straying away from the article, but if Hatchet were dictated to a tribe who didn’t have metallurgy, perhaps it could be perceived as science fiction.