Hypothetical: After horn has sounded during a try?

[Camron Rust]

Ruleswise, the horn is irrelevant. The ball becoming dead is what is important. While that is often coincident with the horn, it isn't always. In this case, that occurs once the try ends (made or missed). So, you hypothetical foul occurs during a live ball, regardless of the horn, and is thus called and the FTs should be shot if they could make a difference. Being before the ball is dead means any such foul would be a personal foul, perhaps intentional or flagrant, but still personal.