Can old deleted records be recovered from Exchange 2003 DB

The environment is a Windows 2003 Standard Edition Server with Exchange 2003 database. This is a small shop of 3 servers and 6 workstations.  An application using public folders was created in 2001 to manage customers through Outlook 2003.  Records have been modified and deleted over years.  Properties of the Public Folders is to delete records after 7 days.

There is a lawsuit against the client for fax spamming. They are currently in mediation and a request for the customer fax data was made.  I exported a file of customer data and turned it over. Now the prosecutor wants to find all records deleted since the year 2001.   He claims he has some fancy programers who can discover this information if they subpena the hard drive of the server.

I cannot imagine this possible because the data on the drive has not been static.  This application and others are constantly changing the hard drive.  Can anyone verify this?  

I'm not a lawyer but it seems the defense is not adequate to the task!  If anyone has experience in this area, I'd be most grateful.