The ability for SCSI to be hot-swappable is functionality of a RAID controller. Most levels of RAID can endure the failure of a disk and not be compromised. Try looking at some RAID controller docs....
The purpose of having a disk hot-swappable is to allow the system to continue running as if there was a disk there to compensate for the bad disk. If you have only one disk drive, that can't be achieved.
Mike
Icabability.Can