[FMadera]

A couple of things:

1. This should definitely be prematched.
2. The R2 has the right to whistle a non-judgment fault that he is certain the R1 missed (stay away from ball handling on this one), such as illegal attack/block, ball down, etc. If the R2 has given R1 first shot on this and is 100% certain it contacted that divider, I think a whistle is appropriate (headsets would help here).
3. If the R1 has a question about the whistle and discusses with the R2, and insists the ball didn't contact the divider, a replay may be appropriate. The final decision rests with the R1.

Just my thoughts.