BOAC,
I don't know the exact circle to land minimums for that 12 approach CL to 30 or if it was at AA's mins. I would consider that there was reported to be precip on the approach segment to 30. I don't know the severity.
With KIN operating experience, I do know that the visbility and ceiling conditions might have made the procedure somewhat "dodgy" as you folks say. On a normal VFR night there are good references with the lights of the city across the bay and the hillsides to the north and east. With reduced visibility the city light/coastal light references may have been invisible, and a circling pilot may be only left judging his approach over the dark ocean and the airport lighting. Also throw it the fine job the B737 wipers do in the rain. Easy work for a carrier pilot, possibly an issue for those that don't practice it on a regular basis. No excuses, just an observation.
Also consider KIN is an ungrooved runway. F40 is an obvious choice mentioned here as well as MAX autobrakes. I would note that I once experienced a rather interesting characteristic with F40 and MAX autobrakes landing on an ungrooved runway not unlike KIN. Each set of main wheel brakes did a fantastic job grabbing the surface and creating as much braking force as possible. The only problem was that one main set was doing this while the other was hydroplaning through one of many puddles. At least the puddles seemed to be equally spaced on both sides of the runway, so the significant yawing averaged out
The crew did land long on F30. I don't know the performance numbers for stopping in the remaining 4000'. Should it have? It did go off the end at 60+mph. That would seem a little high given the available distance and may suggest NIL braking. Not sure if landing near the end of the touchdown still might have given them some problem decelerating on rollout. KIN did have significant rain during that day.