I find it difficult (but not impossible) to open the Mnandi with one hand. In the closed position, the blade sits low in the handle, and without the benefit of a thumbstud, it is not very easy to manipulate the blade open. The enlarged "nail nicks", however, make it extremely easy to open two-handed. They are milled into both sides of the blade, and greatly aid in extraction.
I'd call it a 1.5 hand opener.