Interference

[CecilOne]

This sounds like an "about to receive", interfering with the fielder catching the ball question. If so, then the umpire has to judge whether the fielder was about to receive the ball when the runner made contact.
If "right before ball arrives BR slides into F5 causing him to get jarred and miss the throw" means the runner arrived before the ball, slid legally and did not deliberately hit the fielder or ball; then it probably is a no-call play. The timing is the important factor, but my visualization of the play is "incidental" contact.