Dog training is recognizing which battles need to be fought and knowing which can be left alone. That's why internet training advice is tough, someone may have had a vocal dog they ignored until it was too late, so they are hypersensitive to the problem. Someone else may have seen a problem like yours made worse by dealing with it the wrong way.
We've all given our best advise based only on a few paragraphs description of the problem. I wish I were there to help, but this is the best I can do long distance.
I train with Jerry a good bit. I too suggested to stop fussing so much on lining him and just kick him off. This dogs basics was thorough. 8 months ago this dog was running great blinds and marking was awesome. A little pressure and he went south a little. His marking has even dropped off. He has had some medical issues as well and I believe this has compounded the problems. He had a testicle that didn't drop and has since been nurtured. He was also laid up a few weeks due to a bad cut foot. To me he just isn't the same dog but shows signs at times of his previous self. I think Jerry will get him back to his old(still young) self. Keep training Jerry and take the suggestions you have been given and he will be fine. He is yellow so that is against him lol. I like this dog alot and I like black dogs.
I would not call the dog back. I would put bumper piles down in the field and do momentum blinds. You put the pile of bumpers at different points so that you can quickly kick the dog off. Start handling to the one that is in the closest direction to where you started from. No fussing at the line. The purpose of the blind is just to get him moving. Worry about the handling later.
should the dog start spinning, give it a vocal "back" just when you see him start to turn his head and look back at you prior to the bark. Timing is critical. You may want to try a very low level Nick. Such as a two. But I would not give him a high amount of collar pressure. This would only increase anxiety.
I have a dog did did this when I got him back from a pro. It seems that he wanted to turn and bitch at me. It made him a very confident blind running dog. Momentum blinds can be awesome.
FC Tribute to Justice, JH "Honor"
FC Contempt of Court "Ruckus"
"Prepare your dog in such a manner that the work he is normally called upon to do under-whelms him, not overwhelms him." ~ Evan Graham
“People who say it cannot be done should not interrupt those who are doing it.”
― George Bernard Shaw
The Smartwork System for Retriever Training (link)