The judges made several mistakes and the last one was to call you to the line with a dead bird in plain sight and interfering with the test. You made the mistake of not making sure the "field was clear" before leaving the holding blind. You were trying to help things along and learned the axiom "No good deed goes unpunished." You would have been well within your rights to request that the judges remove the interfering bird and suggest to them that you'd go back a few dogs while they get the test reset and ready. Or as suggested above, simply rope your dog and go back to the truck while they sort things out. Lesson learned: You own the field and have every right ask or otherwise make sure that all gunners are ready and any distractions removed. Most judges will try to make sure of that but they might not notice a white truck driving near the test, or a flock of wild mallards rolling over the field or any number of other things that might make for an unfair situation. Take your time. Look around and make sure they are ready for you and pup.
I certainly hope that after all of that commotion they carried you to the next series and took the interference into consideration at the end of the day.