Had one bad burn then realized the file was corrupt even before the burn

I use an external Bluray writer from Other World Computing and use 15 of the 25 GB discs to back up my important files.

I then burned the third 23GB ghost image file to the TDK disk but incorrectly left the burn speed on 6x even though the TDK's are rated 1x-4x.

After creating my iso file in other programs, I burn my iso file to create my master BD disc on using Toast 9 burning on Pioneer BDR-XD05B then duplicating more and DiscMakers Blu-ray tower.

My very FIRST attempt to burn a single 11GB file succeeded without so much as a hiccup at 4x.