I think I'd have to see it to call that.
Seriously but, I am thinking you would have nothing, if the fielder has possession of the ball then they are not liable for OBS, if runner is not doing anything to cause INT they are ok, so you play on. how am I suppose to know if F6 is studder steping to throw or to lure runner closer so they can get a tag, then throw for a double play?
Now when you get hairy is when the contact is made right after they release the ball on a throw to 1st! Then what do you have?