do they agree or disagree? hard to see inside the heads and know the mindset.
men can sometimes be shy and not ask the questions they should.
perhaps should just trust their good intentions, never mind who their mother might be.
(in an discussion between R. Yochanan and Reish Lakish, it is unclear if they agree or disagree with each other if intention to do a mitzvah over-rides if the actual act is mistakenly prohibited. cases discussed is sleeping with one's wife when she is niddah, and sleeping with sister-in-law as part of a levirite marriage when she is niddah.
also discussed is if a priest finds out he is in fact the son of a divorcee while he is performing the sacrifice. and thus becoming an invalid priest. God still accepts his service...)