Understanding a DVD Media Failure

I was making an archival copy of one of my DVDs onto a Memorex dual-layer DVD+R. growisofs (actually, growisofs via K3b, but I digress) proceeded nicely for about twenty minutes and then failed, emitting the following:

...
4093214720/8467957760 (48.3%) @2.4x, remaining 22:14 RBU 100.0%
4104290304/8467957760 (48.5%) @2.3x, remaining 22:11 RBU 100.0%
:-[ WRITE@LBA=1e9c90h failed with SK=3h/ASC=0Ch/ACQ=00h]: Input/output error
:-( write failed: Input/output error

I was clear that the burn failed while writing a packet to the LBA 0x1e9c90h, but what exactly happened? That is, what does "SK=3h/ASC=0Ch/ACQ=00h" mean? After some googling, I came up with the following:

SK: Sense Key — Sense keys return information about error conditions returned by SCSI commands. According to the SCSI standards document, SPC-4, an SK byte value of 3h indicates that the command terminated due to a flaw in the recording medium or an error in the recorded data.
ASC: Additional Sense Code — The Additional Sense Code is the first of two additional bytes that carry supplementary information about the error reported in the SK. In this case, an ASC value of 0Ch refers to the generic class of errors simply referred to as write errors (see SCSI ASC/ASCQ Assignments).
ACQ: Additional [Sense] Code Qualifier — The Additional Sense Code Qualifier, or ASCQ, apparently also referred to as an Additional Code Qualifier, or ACQ (as in this case), is intended to provide more specific information about the sense code value in the ASC byte. In this case, however, the value 00h means that no further information is available (see SCSI ASC/ASCQ Assignments).

The upshot is: I had a defective DVD+R disk.