Saw this on page 53 of "Cutting-Edge Cycling" by Allen and Cheung:
The time scale in the bottom does indeed go out to ~5 hours, not 5 minutes. I added the blue and orange lines for reference, blue being the 1000w line, and orange being the 1 hour power.
Opinions as to if this is possible? Hunter allen has piles of real data to use, so I'd see no reason for him to fabricate a data set to illustrate a point in his book. Pretty darn impressive if its legit (but my guess is the timescale is accidentally the wrong one)!
Link on google books: http://books.google.com/books?id=vyRI3yqGnNEC&pg=PA53