That policy would make sense, but that involves major caveats that aren't clear from the original description. That works because it's specifically written with "generosity buffer" that (by design) only benefits your grade, and thus doesn't indicate the teacher was falsely labeling the answers as correct when they weren't.

That's not the same thing as the original, which implied "my grading is so random, hope you're lucky on the rescore".

Edit: I had a high school teacher with a policy where she’d add X points to every score from the get go, and you’dlose those if you objected to grading, so you’d only object for misgrades by more than X. But that’s not the same as the original “okay, let’s roll my truth-recognizer dice again!”