Hi,
Not that I am aware of unless you had some kind of backup to disk or maybe backup of filesystem files in a seperate manner i.e. the /usr/sap* and /oracle/* that could be restored.
If the customer DBA had not overwritten the DB and system you would always have been able to rolled back. Since this is not an option I think you will have to start with a clean configuration and build from there. That being said I am not a solaris expert at all maybe move this thread to SAP on Unix and the experts can advise however I think your situation will remain.
Kind Regards,
Johan