Actually your point is not really valid. The company itself is most likely the one that any litigation would be against, not the admin. If the admin has done her job and properly documented it before going on maternity leave, then she can easily prove that it is not her fault to both the legal authorities and her superiors. It would however be up to the company to prove that the 'power user' was adequately trained, followed the processes laid down consistently, documented their activities, etc. in order to avoid any liability in the incident.

It's not a set of 'you didn't do this so you get a fine' type of ideals....modern litigation relating to this is trying to prove that the company did not follow through and do the server maintenance that they should have. The company simply has to prove that it did everything it could to keep it's systems safe (which it should be doing and documenting for liability reasons anyways).

It isn't incredibly difficult to keep logs of maintenance activities, audits, etc.