What is the ruling if one breaks the fast on the day confirmed by a single witness through sexual intercourse (Jima')?

Primary text

If one breaks the fast on that day due to sexual intercourse, the expiation (Kaffarah) is obligatory. This is because the fast was established by the sighting, and breaking it intentionally with Jima' necessitates Kaffarah, as if the judge accepted the testimony. The Kaffarah is not negated by the difference of opinion regarding the obligation of the fast itself.