I haven’t heard any details regarding which rebreather either used, with rebreathers there are too many variables to consider that usually it’s never an incident because someone was using rb a vs rb b. There’s all the physiological factors, equipment maintenance (which can be a very large and meticulous task with rbs), experience on the particular unit, how closely he was monitoring the sensors which tell you your current PO2 readout, those sensors can fail and give you a false reading, this list can go on forever. I do know that the rb used in the Oriskany incident, is being shipped to DAN so they can perform some sort of post-incident inspection of it along with the rest of his equipment. Source: http://www.fox4now.com/Global/story.asp?S=11519332
I’m sure what ever they (DAN) find will end up in an upcoming issue of Alert Diver.