BR runs into batted ball

[SAump]

JV TWP, but it happened. I have been thinking about it all day and would like your input.

R2, 0 outs, outside pitch, RHB swings and makes contact. The ball deflects off hard ground from leftside batter's box near plate and bounces at least belt high out in front of plate about two feet. When B/R realizes the direction of the 1st hop, he takes off for 1B and catcher takes off for the ball. The ball glances off the B/R leg about ankle/shin high and into the grass in fair territory. The catcher still manages to make the out at 1B.

1) Did I have immediate interference, return runner to 2B?
2) Did I have no interference since the B/R helped improve the catcher's throwing lane to 1B and the out on B/R was recorded anyway.
3) Did I simply have a foul ball, when contact was made by a RHB in front of home plate as he cleared the rightside batter's box?

It happened really fast. I chose option 2, although I thought really hard about option 1 and the BC called time to explain that I had missed option 3. I explained that the ball was never inside the RH batter's box and that I let the play run its course. R2 advanced on the play. What should I now learn about a play like this one?

Edited to add link: http://www.nfhs.org/core/contentmana...%20diagram.pdf