I took another look, I can't see anything, red marks show where I have continuity.
I've ordered a replacement ribbon, no continuity there and clearly a different batch. Was there a known manufacturing error with any of these? It seems 470 is shifted a little though not enough to create any visible bridge.
UPDATE:
Still couldn't find the source of this strange continuity between VLCK and D0. Checked again and unwanted continuity was definitely there, screen output was obv garbled. Removed the ribbon, all pads intact and still on the ribbon. Checked continuity on the board and ribbon, both check out OK, no unwanted continuity. No errant solder or debris anywhere, strange that it would jump over the 5V leg. It was fortunate I spotted it, but it remains a mystery.