Using her real name and then reporting the results as “they thought Judge Judy was a SCOTUS justice” seems disingenuous. It’s not like the option that they chose said “Judge Judy”. I wouldn’t even have known that Judith Sheindlin is her real name and not just a generic old lady name.
I would wager the majority of American college grads can’t name all 9 SCOTUS justices (or even all 4 women), and if you’re just guessing then any choice that isn’t obviously wrong (like “Judge Judy”) has around the same chance of being chosen as any other not obviously wrong option.