Yet another INT/OBS question

[sbatten]

Hi, all -- I'm an inexperienced ASA slow pitch umpire looking for a second opinion on an adult rec game I called yesterday.

Two outs, R1 on 2B, R2 on 1B. Batter hits a grounder up the middle, actually a little to the left side of the pitcher's circle, and F1 makes a stab for it, but the ball continues through (untouched).

R1 and F6 then collide as F6 is preparing to pick up the grounder. Ball bounces off F6 and rolls to the side.

I immediately called interference on R1 for the third out of the inning.

R1 argued that since F1 had attempted to make a play on the ball, R1 should be given a clear path to 3B and F6 should not have been in his way. R1's argument, as I understand it, was that he didn't feel interference applied because F6 was not making an attempt to field the ball at the time of the collision, F1 was.

I explained to R1 that I didn't see F1 touch the ball -- which might have changed how I ruled on the collision (it did not look like intentional contact on R1's part). Absent any deflection, I explained, R1 had to give F6 a chance to field the ball.

Comments? It was a friendly game and while R1 was certain he was right, nobody broke any blood vessels in their brain arguing over it. I'm just looking for a more experienced point of view -- I know most INT/OBS calls are HTBT, but could I have ruled that the runner was protected (not the fielder) in this case, by virtue of his impression that R1 was fielding the ball?

And a hypothetical scenario (pretty much unrelated to the original question) -- if F1 had successfully picked up the grounder, then R1 and F6 collided, and F1 threw to F5 for an apparent force out, would you agree that I would be justified in awarding R1 third base? I've called obstruction a handful of times but usually when runners are advancing on base hits; I've never had to deal with it on a play in the infield.

Scott