A rate of 11 m/s equates to approximately 2200 ft/min. That is a standard descent rate. Emergency descent procedures require a descent near mmo/vmo unless structural damage is suspected. It also requires extension of full speedbrake resulting in a rate of descent in excess of 4000'/min. I suspect the speedbrakes weren't even deployed contrary to SOP's and I'd love to know the actual speed on descent. I guess we will have to wait for the full report.