It depends. Are you talking about a poison bird that's down before he gets sent on the blind, or about a diversion bird that's thrown while he's en route to the blind?
Either one is a poison bird blind, and both serve as diversion factors. The "en route poison bird" is the more difficult concept of the two.
How close to the line?
In hunting you'll never be able to predict it. In a test it is pre-determined by the judges. In addition, the concepts involved are also determined by the judges, such as:
- Blind behind the gun
- Blind past the old fall
- Blind through the arc of the fall
- Blind through the fall (completely unfair as a poison bird blind)
Those are standard diversion mark concepts, and the first three are what are commonly taught and tested, both in field trials and in hunt tests. They are perfectly appropriate to use in either testing venue, as poison bird blinds are among the most important field skills for gundogs.
I think one needs to answer the question first of how important it would be in a hunting situation before you can answer whether it should be in a hunt test or field trial. Especially the hunt tests, which are supposed to simulate hunting (ha ha), if it's not something you'd see often in hunting, it doesn't belong in a hunt test.
I'm with you on the "reality" involved in testing! Only hunting is hunting, but I appreciate efforts to include aspects that are at least as realistic as possible in hunt tests. A test can never contain what all hunts do; sponteneity. But "yes", the poison bird blind is among the most realistic/hunting-like concepts. And understand this about any blind retrieve in a testing venue; it is not valid merely because one might need to run one while hunting. It is valid because it is a test of control and a dog's willingness to take direction from a handler. Adding the poison bird concept elevates the demand on training and handling, making it a more elite level of test.
I don't hunt enough to know the answer. When we've been pheasant hunting, it's one bird at a time (except for tower shoots/driven hunts), so there would be no poison birds.
You need to hunt with us out in western Kansas. Multiple birds on a rise is commonplace, and a running crippled pheasant can leave the county in a hurry. If one or more birds were clean kills, buy one is crippled and running, you'd better get that dog on him quickly or he's lost game!