I don't know the official answer to your question, but I do know that many of the tables in the micros database have columns labeled 'last_updated_by' which may or may not be filled in. When they are filled in, their number may line up to an emp_seq, which is the primary key of the micros.emp_def table.
I have noticed that on the the Micros system I have access to, these columns are not always updated. They're likely dependent upon the micros settings and/or version. The security settings can be found in the pos configurator, there may even be more elaborate options for future logging.
Also the micros front-end seems to keep relatively meticulous logs of each transaction (can't remember where in the micros dir tree they're stored). I wouldn't be surprised if the back office had logs too, in a way though, I'd also be surprised if they did.