Looking at the Jeppesen version of the plates dated Feb 2015 it's a bit clearer that it is 8D from the DME.
We don't know which plates the pilot was using, but still an easy mistake to make flying single pilot, and no auto pilot I would imagine.
Looking at the warnings regarding the LOC and GS indications, I think it says that they might not show at the north of the LOC when below GS, so why once the base turn was complete would you immediately convert to a LOC DME approach if you never saw a GS indication?