Hmmmm, I don't know about that.

You still have a mechanical advantage on a bike whenever your chainring is bigger than your rear cog. Which it's rare to find a road bike with lower gears than that - mountain bikes, yeah.

Plus, it seems to me that the body mechanics of standing to climb is hard to differentiate from a slow motion run... except that you're creating forward progress on the up-stroke as well as the down-stroke, and using your arms to generate more force.

I think that guy who passed you was a freak of nature.