>>> OCR are a private company
No it isn't. OCR is part of Cambridge Assessment, which is a brand name of the University of Cambridge Local Examinations Syndicate which, in turn, is a not-for-profit non-teaching department of the University of Cambridge.
It's not their first error though
https://www.bbc.co.uk/news/education-13627415
but errors were occurring back in the days of O-levels and CSE examinations too. (On a final review of a CSE Mathematics exam for the examinations panel I served on, I spotted an error that had somehow gone unnoticed by the twenty mathematics teachers who'd all reviewed the proposed paper before I got to see it. If I'd not picked up on it, all those students who'd chosen an incorrect response to a multi-choice question would have been awarded a mark for it, whereas those who provided the correct response would have been awarded nothing).