A 1920 census records shows a daughter-in-law, and two sons, one single and one married. The indexed information shows the daughter-in-law as husband to the wrong son. There is no way to edit this error.
They're rolling out the new "correct anything" interface starting with U.S. censuses, so you'll probably be able to fix this relatively soon.
In the meantime, the index has served its purpose, despite the error: you found the record.
It is very annoying when you cannot correct indexed information that is wrong. All indexed information should allow corrective information to be submitted and included in the search results.