It seems extremely unlikely, but a couple of things....
When running a mile that fast, 36 seconds is a LOT of time. It's kind of like a pitcher's fastball increasing. If a guy goes from 85 MPH to 94MPH, that's the difference between playing with Schaumburg Boomers and Chicago Cubs. A guy who increases his heat from 96/97MPH to 99/100MPH is the difference between a potentially really good closer to and unhittable one. Heck, the difference in a gold medal and 5th place in the 100 meters is what....0.7 seconds? When you get to an elite level in speed events, a little is a lot.
The other thing would be that if he does indeed have an elite level of endurance, the difference in the stride of someone 6'9" and a guy 5'10" is what....three feet? It's tugging 230 around vs 170 that makes it seem relatively unreasonable.