Understanding the JK latch
(Just attempting to understand the OP for now; will update this answer shortly)  

Say initially Q=0.
Look at the bottom NOR gate. It's output will change if one of its inputs becomes 1.
Now, apply C=J=1.
Then the AND gate output becomes 1 which makes the NOR gate output become 0.  

Your question is: since the NOR gate output changed to 0, this would make the AND gate ouput 0 which would makes the NOR gate output change back to 1 and so on. 

Here NOR gate is acting as an inverter with one input tied to 0; AND gate is acting as a buffer. So you have a ring oscillator which keeps toggling forever. Is this your question?