The high level players will memorize all 3 letter words and sometimes 4 letter words as well. Their scrabble-dictionary vocabularies are incredible. Here's an old article about the highest score ever (at the time). It included a triple triple worth 365 points alone for QUIXOTRY.
https://slate.com/technology/2006/10/830-how-a-carpenter-got...
the high level players will memorize all words until 9 letters, and some even know those and beyond. I know all the 2-8 (approximately 80K words) pretty well, although not as well as I'd like.
I don't understand why the article portraits the described game as unworthy of the high score. An experienced player will always hedge, and thereby the high scores will all go to less bothered players gambling their way to a win.