Please give a legit explanation why team Thailand lost two points and does not allow substitutions s

The incident clearly demonstrsted indiscretion on the part of the First Umpire (from Mexico) in unnecessarily issuing 2 red cards without justifications despite the fact that he should have asked for an innspeclion of the IPads to see if the touchscreen was really working before rushing to penalize the Thai team at such critical moment in the deciding set of the match. His contention in giving the 1st red card that the Thai coach was using delay tactics when he requested a challenge was ridiculous as the Thai was leading 12:8. Rather, the Thai should have tried to call it quits asap! On the 2nd red card, he claimed the Thai coach was attempting to make substitutions without touchscreening. This is also ludicrous as the practice has been going on and on in every match and by every team. It is not sensible for any team to violate this rule as it is so easy to catch by the umpire. In a nutshell, this Mexican umpire should be sent for retraing before committing further mistakes to damage the IFVB's reputation.