My favorite way to close the small sebenza:
Holding it with the spine down (edge up), push down and to the left on the lock bar. It should move over very easily.
Now, swing it down and bump the spine against your leg. This will close it just a tiny bit, but enough to keep it from locking again.
Then, turn the knife in your hand, and push it closed against your leg.
I find this the safest and fastest way to close the small one-handed.