[NFump]

Okay, first things first. WWTB, you keep calling this "batter interference". That's usually on a batter, in this particular sitch it's a runner. Interference by a runner on a thrown ball must intentional. J/R doesn't touch this? I beg to differ. Page 81 Note: Apart from being outside the 45-foot running lane, a batter-runner can only interfere on a thrown ball if his action is intentional and hinders a fielder. For instance, a strike three where a batter becomes a runner is treated as a thrown ball situation, and such batter can only interfere subject to the dictates of Section II, Subsection B. (page 78) Here's what that says:

B. Thrown Ball (including tag attempts)

It is interference by a runner on a thrown ball or tag attempt only if such runner

(1)commits an intentional action to interfere that disregards his try to get to a base safely, and

(2) such action hinders a fielder trying to throw or trying to tag.

Again, intent is the determining factor. Without an obvious intentional act this remains a live ball.