Ah, but you should be able to hit it while drafting with aero bars.
My point here is that it's not the bike that makes you go 40mph - it's the "engine" (the human) and the environment. Expensive human-powered bikes aren't going to magically turn someone who tops out at 20mph into someone doing twice that.
At threshold power, I'm guessing more like 22-23mph.
And, not to toot my own horn, but that's a pretty damn fit experienced cyclist.