Sudden Rooster Death - ?!?

I’m looking for answers, but I don't know if there are any.

Earlier this year, we added some Black Copper Marans chicks to our flock from a very respected local breeder. They are about 14 weeks old now and have been healthy the whole time. We did a slow flock integration, and things were going really well.

The cockerel had just started “roostering.” By that I mean he would alert when treats were added to the run, do his little dance, and put himself between us and the ladies until he felt comfortable. No signs of aggression at all. Just stoic and watchful, which is exactly what I want in a rooster.

Everyone is currently being fed:

• Kalmbach Chickhouse Reserve, 18% protein
• Kalmbach All Natural Non-GMO, 18% protein
• Scratch and Peck Grower, 17% protein, fermented 3 to 4 times a week, usually every other day

We have had no sickness, no injuries, and everyone has looked healthy.

Then on Thursday, my husband found the cockerel dead. He had been totally fine that morning when I fed and watered them. It couldn’t have been too long before we found him because he wasn’t very stiff yet.

He had food coming out of his mouth, and there was also food present in the esophagus area right behind his beak. I put gloves on and gently massaged down to see if there was food all the way down, but there wasn’t. His crop was not large or sour. I’ve dealt with sour crop before, and this didn’t look or smell like that.

They all have access to bowls of grit in two different sizes. I also haven’t had them out foraging this week because I just planted out all my dahlias and they would absolutely destroy the fresh rows, so they didn’t suddenly get a big dose of plant material or anything unusual.

The only thing I can come up with is that he choked, though the food looked pretty consistent and smooth, not like there was one obvious object blocking anything. It almost looked more like something happened and he regurgitated food while dying.

I’m really at a loss and looking for possible explanations. Has anyone seen something like this before in a healthy young cockerel?

I’d also like to go back to the breeder and ask if they’ve ever had this happen before, and possibly ask if they have another nice-tempered cockerel available. But I’m worried they may be hesitant because this bird died. I take good care of my animals. I've had older hens up and die on me, but at 7 years old, no real surprise, but never a young bird like this.

Any thoughts or similar experiences would be appreciated. He was so damn pretty, this is frustrating.