Thank you for your comment and the link. I can't blame anyone because I do not know whose fault it is but I think it is a responsibility of hte whole team to keep such important information like posting key away in safe place. But also it is team who should be first starting the investigation and finding the cause of problem.

We should not put the responsibility from one shoulder to another. We all remember like in real life it is a team work no matter if good or bad things happen.