Interferance? If so, what penalty?

[akalsey]

Under Little League rules, with a runner on 3rd and 1 out, the game is tied in the bottom of the 6th with the home team at bat. Two strikes on the left-handed batter.

The pitch comes in and the batter swings late, strike three for the second out. The catcher bobbles the ball and on the batter's follow through the bat hits the ball, sending it toward the first base dugout.

R3 heads for home, but I call interference on the batter and return the runner to third.

On the first pitch to the next batter a long single into the gap scores R3, ending the game.

Two questions. Although the act was clearly unintentional, was interference the correct call? The rules that appear to apply are 6.06(c), 7.09(d), and 7.09(f) (but 7.09(f) seems to be a stretch).

And what would the correct penalty be? I can't call the batter out since he's already out. And all the rules covering batter interference have the batter out if there's two outs and the runner if out if less than two are out. Sending the runner back to 3rd just feels wrong. If it weren't LL, the batter wouldn't be out on the third strike since the catcher hasn't caught it, so he could be called out for the interference.