You can easily open a Mnandi one-handed. In fact, you can open it with either hand. It has a kind of opening groove rather than the usual Reeve thumblug.
It's a real favorite of mine. For an elegant gentleman's knife, it is still sturdy and sharp. One day I was about to take my Spyderco Native with me, when I pulled out the Mnandi and compared blades. They both had the same length cutting edge.
The pocket clip is excellent, and since the whole knife is so light, it works well clipped to a shirt pocket.