Now i got you.
This maybe true. In general, SCSI has the capability to lock the door
or to ignore hard-coded unmount/eject commands until this will be released by the software.
You may control this via the SCSI Mode Select parameter list. However, the software
handles this for you automatically.
Fo be able to eject the media you must unmount it from the device before you
should be able to press the eject button. It would not be good for any software
if you would be able to eject during a read/write process.