Al
Sometimes when fishing the bung, it will twitch a fair bit before moving away or drawing under. Perhaps I am wrong but I feel this may be the same fish and therefore the same 'take'.
Personally, I generally only lift into the fish when the bung moves off or draws under. I wonder, too, if the twitches are like 'line bites' when carp fishing; i.e. the fish has hit or swirled at the fly but not actually taken it and hence these register as twitches on the line.
Anyway, well done on your good catch but a lengthening of the leader to 8'+ should help and, remember, loads of takes are better than no takes at all !!
Ben