Yeah, the collapses (Mickelson's and Van de Velde's) were of a different nature -- Phil's was due to atrocious decisionmaking; VdV's was simply a pressure choke.
van de velde made really bad decisions.
1. he should not have hit driver but got away with it when his drive was so bad, it went over the lateral creek instead of in it.
2. his second shot should have been blasted into the grandstands where he would have gotten a free drop near the green instead of dumping his second into waist high junk.
3. his third shot should have been lateral into the fairway and his fourth would have been an easy pitch to the green and 2 putts to win, BUT NO, HE WENT FOR THE GREEN ON HIS THIRD AND DUMPED the ball INTO THE WATER.