It may happen but I have never seen a diversion bird or bull dog thrown on the return in a FT. With that being said I very thoroughly teach poison birds when doing pattern blinds after TT. I teach by throwing a bird then swinging to the opposite side of the field and run to a known blind. Gradually getting closer to the bird running behind the gun station that throws the bird and eventually running under the arc and then just past the bird on the ground to known blinds. I do throw diversions on the return using the same process and usually only takes a quick toot toot to get them returning, rarely needing pressure.
I rarely let them pick up the poison bird or diversion bird until they are very good at ignoring them. When the dog is proficient at this I will throw a bird and run three blinds, behind the gun, under the arc, and past the bird then let them pickup the poison bird. I prefer to break it down and make it as black and white (is that phrase politically correct?


) by teaching before testing them.