Not to diminish Carmack's significance and genius, but, from waht I can tell from the first minutes of the interview, he knew he was going to be awarded, so je had plenty of time to prepare and rehearse his -- very inspiring, I should say -- speech.
Recent examples:
2h50 2013 QuakeCon keynote https://www.youtube.com/watch?v=Uooh0Y9fC_M
2h20 2014 SMU talk https://www.youtube.com/watch?v=3_oTvUl88hs
1h30 2014 Oculus Connect keynote https://www.youtube.com/watch?v=nqzpAbK9qFk