Toss up? Obstruction and Interference on same play

B1 hits short gapper to right. R1, slower than molasses, rounds second running into an apparently oblivious F6 (obs) and continues on to 3B where throw somehow just beats him to the base. R1 does a very fumbled slide into 3B as BR, a speed burner, motors towards second. The fumbled slide goes off to the side into F5 (int) interfering with F5's ability to get a throw off to 2B and the throw just misses BR.

Ruling? Interested in finding out how many have same opinion.