Thanks for posting the link to the video. It took 11 minutes to get the gentleman out of the water, plenty of time for severe hypothermia to set in. See the chart in this link.
http://www.boatsafe.com/nauticalknowhow/hypothermia.htm
Certainly the stress of the situation in addition to the cold probably hastened the gentleman's death. Sincerest sympathies to the family and friends.
Hopefully a painful lesson to be learned for all of us.