How did Hsu Jen Hao lose so miserably with that kind of score in two sets, players of his calibre aren't supposed to do that at such a high level tournament. To suffer one set in single low digit score is not too unusual - it has happened to a number of players here, eg Akane Y and Jindapon - but two sets, one 7 and the other 9 points is almost unheard of.
I actually watched the first set before switching to the Boonsak vs JOJ match, and didn't notice anything wrong with HJH, no apparent sign of injury or suchlike, he appeared to be moving well.