That's not possible. The only thing I can think of is that you were so excited the first day you played it, everything seemed to be moving faster. If you can sprint in third person, you can also do it in first.
I'm afraid it is possible as I encountered the exact same thing last night.
Sometimes, in first person view pressing L2 causes my character to sprint for about 3 steps then he goes abruptly goes back to normal pace. If you switch to third person he sprints until the stamina gauge is depleted, as normal.
This doesn't happen all the time and there doesn't seem to be a pattern to it. Odd.