Only because he was the opening leg... Both Gardner-Webb and Lezak's split was better than Phelps' and of course Lezak's was world record caliber but unofficial of course.
GWG and Lezak had the advantage of a .6 sec (typical) relay start. They would beat Phelps in a flat start race. But Phelps flat start time was .01 off Bernard's WR set this year. Pretty damn good swim for a guy who trains for 400s. If Phelps swam against Bernard (or Lezak) in a 400 free he would beat them by 10 seconds or more.