No, replace "sued" with "humiliated". Every time. It just sounds more prudent to say "legal risk" than "we're worried a member of staff will make us look like absolute morons" or "we're lazy". It's obvious when you think about it.

"We didnt hire her because she seemed like she might get pregnant" isnt the kind of feedback most people write anyway and if they did a 2 minute pass via HR is enough to eliminate the risk.

The companies that are actually worried take pains to tell you what not to say during the interview. This is rarer than you'd think. Most companies aren't actually that worried about getting sued over interviews. That doesnt stop them from tossing this lame excuse at you though.

This is fact.

This is the only correct answer.