Instuctional video with Doug Wedell, chief instructor of Seidokan Aikido of South Carolina, illustrating basic ways to throw with the staff (Jo) from one hand grasp (Katatedori).
If uke let's go, generally three things will happen. 1) Uke won't have to fall (a positive for uke). 2) Nage will have free control of the jo (a positive for nage). 3) Uke will be open to strikes from the jo by nage (a negative for uke). Unless you know nage is a very benign person and in full control, we stress that for safety and self defense reasons uke should not let go in the middle of a technique as the jo becomes much more dangerous to uke (accidentally or purposefully).