I'm surprised anyone would have ever thought otherwise. I think an OB-first cut is possible from this set up but it would require a lot of swerve with a perfectly accurate hit- too accurate to actually attempt in play.
I think the key lies in understanding how much that rail compresses, and how efficient the inside spin can be at "torquing" the CB back off the rail. I could always tell the difference between a rail-first hit and a ball-first or simultaneous hit (in less extreme cut shots). But seeing how much that rail compresses, and how much that CB can "turn" coming off the rail makes it easier to comprehend.
Maybe one of our engineer-type AZB members could calculate the angle required to shoot the CB from position 3 and miss the OB on the way to the rail. The OB is centered 7.875" away from the short rail, and is frozen to the long rail. The CB is centered 5.625" away from the short rail, and is positioned along the center line (ball spotting line).
Whatever the answer is, I'm still surprised that the CB can "torque" off of that rail enough to make contact on the way out from the rail.
Just thinking out loud here...
-Blake