Two tricks come to mind......first you can try a longer check cord, and have helper shoot the bird.... you run with cc in hand, and that way there isnt any fart around time fo rthe dog....you are immediatly there in sight for the dog.....on my natural work.....this will work well, along with allowing the dog to carry some, but he/she doesnt come off cord till it proves to you that it understands what an how.
Or get the obedience good an tight....at the start without game or the retrieve...have it collar conditioned and ready before the retrieve work starts back up again. Then when you have it getting back "here" almost instantly......start doing a retrieve or two with the same set up as you have been doing the ob work.
Dog is creature of habit.......when the ob work is going on, and you have overlayed the here work, to almost flawless...dog gets used to that situation......and it will start getting snappy when you say here.......along with later when you add a retrieve.....it is used top being snappy without a retrieve...it overlays to still being snappy...but with the retrieve, it will take a little bit, but once it starts showing itself, it will work out. Thanks Jonesy