Yeah let's face it, Mitchell was just lucky. All he had to do was press a bunch of actuators, a task that requires no skill and takes almost no time. Even if he knew what he was doing, he was just an average skilled player at best. If he had a similar path in a Season 3 temple, he wouldn't make it out with 1:06 left on the clock. I always felt like some of those Season 1 winners (Mitchell, the Silk Ladder kids), would choke in a later season temple. And Mitchell would be no exception to that rule.
But at the same time, the contestants from Season One had less of an idea of what the show was about; by Season Three, the show was much more established. Comparing Season One runs to Season Three runs is kind of a low blow, since the layouts, room difficulties and general paths taken were so drastically different. If you were to compare him with a contestant who needed to contend with the Tomb of the Headless Kings, King's Storeroom, Jesters' Court, and Chamber of the Sacred Markers, clearly the difficulty for the latter was increased.
While it is pretty improbable that clearing seven rooms in a Season Three layout would only take 1:15, it is also impossible to directly compare Mitchell's route to a Season Three layout since the access from the Ancient Warriors to the Jesters' Court was cut off.
However, the objectives the Season Three player would have completed would have been the Ledges, Pit of the Pendulum, King's Storeroom, Room of the Ancient Warriors, Jesters' Court, Dark Forest, and Quicksand Bog. The King's Storeroom would have been more time consuming and the Jesters' Court would have required a bit more effort, but for the most part, the difficulty of the rooms would have been just about equivalent.
On the other hand, in comparing Season One contestants to one another, where the contestant pool had the same knowledge about the show and the layouts and room objectives were generally consistent, Mitchell did pretty well. He didn't get turned around or try to backtrack (like so many Season One runners did), and he didn't delay, hesitate, or get tripped up in any rooms (again, unlike most Season One runners). I'm not saying that Mitchell was the very best, but I think that people are too quick to disregard him, when in reality he cleared seven rooms and did so pretty efficiently. He just got lucky with the fact that the difficulty of his path was low (something he didn't necessarily control, but he seemed to know exactly where he wanted to go).