Okay, so this time I tried the command:
growisofs -dvd-compat -Z /dev/rcd0c=image.dmg
It failed the same way, except this time the error ends with:
....
/dev/rcd0c: closing disc
/* The following messages have a blue foreground */
cd0(atapiscsi0:0:0): Check condition (error 0x70) on opcode 0x28
SENSE KEY: Media Error
COMMAND INFO: 0x3e
ASC/ASCQ: Unrecovered Read Error
/* It repeats this 3x in succession then moves on to: */
/dev/rcd0c: reloading tray
:-( unable to reload tray: Input/output error
# _
