Both serves, particularly the first one, seem to have the ball hidden by the head. The issue isn't so much calling the serves, though the umpire is very unlikely able to accurately judge the motion from his seat, but that he completely fails to communicate what the issue was, and calls the second serve before the motion is even finished, therefore significantly lowering the chances of rectifying the fault.
The ITTF has an official guide to umpires and referees that includes hand gestures and verbal communication to convey the part of the service that was faulted. By the date of the document, it's been around for at least 10 years.
Regardless of the accuracy of the calls (which is always questionable, given the long-standing issue that the referee isn't in a position to fully enforce service legality), there was a training issue with the umpire and the main referee's answer reported by Yokotani is also insufficient.
Umpires &Referees – Essential Document
New Hand Signals for Illegal Services
