The trial of Socrates
In a cerain tradition of writing on matters Hellenic:
We have scant evidence for what happened at the trial of Socrates - a few (partial) accounts and a general understanding of Athenian procedure - the accused was brought to debate their innocence - with no rules of evidence - before a jury of 500 on two occasions, the second of which could result in a majority verdict eitehr way. Rough, ready, democratic - but not very just.
After all, popular prejudice and faction could have a heavy part to play in that process - and the very act of bringing a charge could come from politically motivated opponents. Socrates was charged with corrupting youth and disbelief in the gods - i.e. thought crime.
It should be noted, though, that the crime only related to Athens, and he was, apparently, free to flee if he so chose (he didn't) but the principle of association rather than of universalist crime was at the heart - one way or another, Socrates would be expelled.
We, of course, do not know the evidence, nor do we know (fully) Socrates' politics. He, certainly, had made himself unpleasant, and probably had failed to curry favour - his political views we do know were dubious and suspect at teh time (even without knowing their content) and probably anti-democratic.
I'd suspect that nowadays a good union rep. would have made mincemat of the case - nowadays we expect formal warnings, informal attempts at resolution of problems, investigaitons and independent recommendations - we simply would not allow a recourse to the severiest mechanism to hand as a first recourse.
Socialists can hope that they would never vote for guilt by association nor thought crime - but really, before that comes sympathy and understanding that maybe a recourse to the rigours of law is itself unjust. Remember, the dreaded Star Chamber began as a positive mechanism to protect and assist the judicial process; but when it began to be aggressively deployed its nature changed. Systems are shaped as much by their uses and uses.