Obstruction or Interference? Tricky call

[RPatrino]

I'm trying to get my arms around this play, and trying to see where Durham is coming from.

For argument sake, suppose you ignore the initial muff, and you take this play from the point of where F1 is attempting to "field" the ball and he is prevented from doing so by the BR in the baseline. His contention is that because F1 is not treated as an infielder, he is 'protected' on this attempt to field the ball, albeit his second 'try' at it. Taken in this isolation, you could argue interference.

My question is can/should you ignore the initial attempt to field the ball and in essence protect the F1 in this case during his second try at fielding the ball? Taking this further, how many attempts would an F1 get at fielding a ball?

My initial judgement on this was obstruction, removing the F1's protection at the point of the initial muff and the distance he ran (chased) the ball to retrieve it, being more than a reach.