GlobalMac IT can help with limited E-Discovery by sending or showing reports that are available in certain services. Also, if you need to confirm there is no data missing form the file share that a person may have left on their desktop.
If you feel this person stole proprietary data you should consider hiring a firm that specializes in this type of work. This type of work borders on the edge of Computer Forensics for legal purposes, and GlobalMac IT does not speciliaze in this field. We can make a recommendation for a firm that does this specific work.