"it takes 60 to 90 minutes to transcribe even a small portion of it.I can think of another really exotic language with no words for hello: French. The closest to a "hello" you can give someone is to wish them a good day or good health. I can't say I know much about transcribing, but it seems to me that the speed would have to do much more with familiarity than with complexity.
There are no words for “hello” or “good-bye,” for example. The closest to a “hello” you can give someone is a phrase for “How are you?” – “e : si : raci : ci.”
Finally, it's interesting that nowhere in the article is the language actually named. It's simply called the language of the Wichita Indians.