Using my dailies profile you SHOULD end up first each time. Reason being it actually takes off before forcing you to dismount and get on your serpent, making it so you fly as fast as your current mount training allows (150%, 280%, 310%) and then finishes the race. Usually ends up halfway to the 2nd mark before the race even starts! Accuracy of making each mark is about 98% (sometimes it stops JUST short of one, but nothing abandoning the quest and restarting won't fix)