After all, is just a man sueing a nation. Is not a trial between USA and China, nor UN or EU against China. If a country / UN / EU would win such a trial, they could force China to pay somehow. Or, at least, to issue severe penalties for China in case China would not want to pay. But a man?! What can a man do to force China to pay him 20 trillions, in case he would win this trial?!
many lawyers do random lawsuits for huge amounts all the time. most never go anywhere
there will however be what is known as a public inquiry. which is were using hindsight everyone can learn from the past. and also find the mistakes.
work out if some mistakes were excusable (caution vs over reaction) and which mistakes are malpractice
after that. those affected by any malpractice stuff or anything. can then take it to court.
but for now anyone can file a claim for anything and any amount.. it does not mean things will en up in a guaranteed trial.
im not going to go into the ridiculous idea of that guys suit.
but if it had merit al local court he can escalate it to supreme, and then after that international court. where 'sanctions' can be put on a country
but these kind of silly ambulance chaser lawyers dont follow through or plan to. they just hope the other side pays up a small 1% just to go away