Don,

Veritas, in conjunction with Tivoli wrote an API for Backup Exec to TSM 
communication.  It's installed on the Backup Exec side with the "IBM ADSM 
option" that Backup Exec provides (it's an add on).  I
don't know exactly how it works "under the covers", that's difficult info to 
obtain from either IBM and/or Veritas.
As for the "strange" output you see from the "show session" command, that's 
correct.

Platform: LA4701S001: pulled from a Veritas Registry entry (that we hack) is 
the name of the Server
ID: LA4701S001BE: also pulled from a Veritas Registry entry (we also hack) is 
to differentiate the Backup Exec session from a plain old vanilla TSM node.
Also, the last event was definitely not a restore in this instance.

Regards, Joe