The people investigating this claim that much of this is undocumented. I don't speak Polish nor have access to any of the primary documentation for the train.
At least one of the trains had its DSU (Dokumentacja Systemu Utrzymania - Maintenance System Manual) linked online (it's specific to that one train). It should be enough to perform full maintenance.
Nowhere in it any of the "lockouts" are documented.
We may see more info next week as they are scheduled to present at the 37th CCC. https://events.ccc.de/congress/2023/infos/index.html
Q3k is active here, https://news.ycombinator.com/threads?id=q3k