I think the article may be technically correct, but is misleading.
It is true that no amount of body (i.e., the rider's body) lean will turn the bike.
You must lean THE BIKE in order to make it turn. We lean the bike by counter steering. I doubt anyone who rode the bike in the article had the guts to lean the bike over without the ability to steer. Once the center of gravity was out of line with the wheels, the bike would fall over.
When we steer, we are essentially moving the wheels out from under the center of gravity of the bike and the bike leans over the opoosite way from the steering. Gyroscopic and centripital forces and your body position keep the bike from falling over.
If you think about it, you will realize that a lot of the time we keep our bodies vertical and lean the bikes over in turns. And sometimes (say to avoid that branch aimed at your head) we will lean our bodies out ot the side and keep the bike vertical so it goes straight.
This is a pretty simple explanation and there are other forces involved (braking, acceleration, rotational), but if memory serves my is basically correct.
Mag
BS Physics '92 (see I do know something about these things).