A bit of information. From the Boeing FCTM for 75/6. Not the entire story but the first para.
During a partial gear or gear up landing, speedbrakes should be extended only when stopping distance is critical. Extending the speedbrakes before all gear, or the nose or the engine nacelle in the case of a gear that does not extend, have contacted the runway may compromise controllability of the airplane.
As a current 75/6 pilot I can only hope that I can aspire to the outcome achieved by these guys. I would suggest the deployment or otherwise of the speedbrakes is of little consequence given this outcome.