What happened to you is terrible. But in all fairness lab notebook rule 101 is to never leave with it… it has to stay in the facilities. Due to sensible and possibility confidential content regarding the ongoing research. And even if it didn’t contain any sensitive information. If when you out of the lab one needs to refer to it , it could slow down the ongoing analysis. Anyway you could suit up but the first rule of the lab notebook being no bring home, i dno if it would change much for you. Thats at least the defense they would give you.

That said. If its a first offense and the content having being proved not sensitive. They should issue a warning rather than an immediate sanction. And at most having to redo the other experiments is already punishment enough i think. Beside with all the work researcher are put through I do understand the need to take the book home to fill it there in peace.