All those listed by Vis are irrelevant here...
And why are you so eager to find out who it is?
...unless we're talking about anonymous denunciations of each other out of envy, of course.
4) The laws were normal back then - now the laws are awful... So, this is nonsense!
In the storage room, they started a conversation: someone criticized the tools, someone criticized the supplies, someone criticized the planning. Isaac didn't say a word, he was just writing out invoices with a chemical pencil. But it became known (and probably they orchestrated it), everyone pointed fingers at each other, saying who said what, and according to point 10, they all received ten years. Kagan also went through five interrogations, but no one could prove that he said a single word. If Article 58 had been narrower, they would have had to release Kagan. But the investigator knew his last resort - point 12 of the same article - failure to report. Kagan was given the same ten years for failure to report.
Gerasimovich is serving his second term; he has "Article 58, paragraph 1-A, through paragraph 19," that is, treason through intent.
He didn't commit treason, but he also didn't prove that he came to Leningrad in the first days of the war not to wait for the Germans.
Where do we end up when we save the world?