Evening Potter! The elevators getting in the way during loading is actually fairly rare and only becomes an issue with outsize loads. I can't really think of more than two or three occasions where I encountered it during my 16 years on the thing.
This is something that can be simply contained by an extra "Flight controls..........P Checked" in the ERO pre-taxy checks. I'm guessing this crew were perhaps working relatively hard - awkward load, in the dark, time pressures perhaps, Captain and Co busy punching things into the CNI/FMC and having to hold the controls back was just taking one of them out of the loop. As you say, airmanship and management clearly apart came and the holes lined up.
Terribly sad indeed; a busy crew trying to do their best but sadly, and fatally, they let their guard down