Well, I've never run into this before... I couldn't set the hook.
I mostly fish from a boat in a lake. I was using the electric motor along the shore line, casting a streamer fly into the grass and then bringing it 5 or 6 feet out into the deeper water before recasting With peacock bass, you don't have to "set the hook"... they hit with such force and then run that hanging onto the rod is what you need to think about. Just keep the fly moving and don't stop.... the peacock bass will set the hook for you.
There were also some small largemouth bass hiding in the grass line. They too hit hard and ran. But several of the little largemouth just followed the fly.... and followed, and followed. No matter what speed I moved the fly, they wouldn't take it. With the rod almost straight overhead, the fly stopped, and slowly sinking, the little bass finally took it.
I was using a 13 foot rod, 14 foot line, and about 6 feet of leader... mostly laying in coils in the water at my feet. The little one pound largemouth is slowly swimming back toward shore with the fly in it's mouth and I'm flailing away with the rod to set the hook. The fish was too close, and my line was too slack.