The author seems to contradict himself in the conclusion: while earlier he states that the Android share icon is also used by ShareThis, and that variations on it comprise the majority of search results for the term "share icon", he then concludes by saying that the Apple/iOS icon is "suitable to use in a general site/app", while the Android icon is "suitable to use in an Android app".

I think the author's own greater familiarity with one icon (by virtue of being an OSX/iOS user) has led him to make an overreaching conclusion about the wider population.