You can listen to the whole thing here:

http://archive-server.liveatc.net/kg...2014-1400Z.mp3

On several transmissions he clearly does sound hypoxic. With hindsight it is pretty easy to realize but it would be difficult to pick up on it at the time. He does say "indication is not correct with the plane" at 4:10 and asks for even lower than 250. A first hypoxic transmission is 7:15 - 7:35 (first he "empty keys" a transmission, center tries again, then sounds somewhat fatigued / slow.) and at 8:10 he has unintelligible transmission.

At 8:44 there is a clearly hypoxic-sounding transmission. His response is "Kilo November 900 Kilo November" with slurred speech. By 10 minutes you can hear mic being keyed but no consistent response.

Sad. Hope the manufacturer and NTSB figure out what happened to the hardware.

Can anybody here comment on personally doing hypoxia training? Was it worth it?