I assume it was to avoid a delay of game, but that was one of the weirdest timeouts I've ever seen. And maybe they were THAT nervous about moving an extra point back 5 yards in those conditions, but man, I think I would have much rather taken my chances on the longer extra point vs. sacrificing another timeout that you very well may have needed.
In general, I think coaches have come a long ways in terms of using analytics in their decision-making, but coaches/QBs sacrificing timeouts to save 5 yards (or in McD's case, to get the defense lined up correctly) as often as they do is maybe a miscalculation in a lot of scenarios.