I found the notion pretty shocking how deeply the rescoring affected people. If the test writers couldn't even get it right, why fault the test takers. I get it... rules... but it still feels unfair at some angle.
It does suck for the people who though they had that one right, it is distressing to be shown one score and then later find out that the real score is lower. That should have been avoided by having an official recourse window before publishing scores, so when problematic questions are annulled then people only see their actual final score (in my country a recourse window is standard for all public exams).
One of the ones you got 'correct' is annulled - now, you got 8/9 correct. You scored 88%.
Everyone who gave the answer 3 was initially scored as correct but then had it annulled and saw their overall scores drop.
30 points is a lot. I had a perfect score (1600/1600). Getting a 1570 would have been significantly different. This is probably worse at admission cutoff thresholds.
Although I'm not sure how the SAT assigns the scores - I don't think it's as simple as a percentage correct (otherwise the score would simply be out of 100), and that there is some kind of normalization they do? Can't remember... and it might have been different then anyway.
The effect of noise on your score is supposed to be around 30 points. A 10-point effect is too small to measure. How can that be "shockingly deep"?
1. You can't award a bonus question to a subset of people, that is not a fair way of running a standardized test. You can't score some people as x/154 and some at x/153.
2. The old score was just plain wrong, so using it in any way is unfair.
The truth is no one got that question right because there was no right answer available. None of those available answers is "righter" than the other so it is not fair to assign a higher score to one of them like you proposed. Those people that got a higher old_score also got that question wrong, so their old_score is as wrong as any, and awarding them this unearned extra point would be unfair.
The only two fair options would be: to annul the whole test and make everyone retake; or the one taken where they annul that one question pretending it never existed and score based on the remaining questions (with each remaining question now being worth a fraction more). And this later option is in fact very fair, I don't think there is any real argument against this being fair.
It does suck that people were initially informed a wrong score and then later were disappointed with their real score. On this line I find it absurd that the SATs don't have the recourse period before they release the scores, and instead just releases the tentative scores as if they were real. This would all have been avoided if they heard the recourse and annulled the question before publishing results (as pretty much any serious exam around the world does it).