I’ve never got less than 96% on a PTS and I wouldn’t consider myself particularly good at assessments
It opened my eyes somewhat when I started Driver training and had to start taking assessments which weren’t mostly multiple choice too.
70% on a PTS indicates there’s probably an underlying issue that the participant wasn’t “getting” I agree. I can’t remember exactly the amount of “points” on offer on a PTS (plus different TOCs vary), but there would be around 80 I’d imagine? That being the case, 70% would be 56 correct, which is very low for a largely multiple choice test.
As I said, different companies have different pass marks, SWR was always 86%, but GWR is 91% across the board (or was but the way in which assessments are carried out has changed now).