Hen killing detective - please help

[Sublight]

Please help me work this out... I'm in New Zealand

1. We have a small flock of Orpingtons and one little buff girl has managed to get out and about for a wander on most days. We don't worry too much about this as she has a wee rummage around and regularly goes back to her pen to see the girls again.

2. We have two young (10 months) labrador x boxer dogs who have grown up around the chooks and have been interested but not aggressive towards the lonesome wanderer. We always discourage them from approaching her and if they do she squares up to them and at least once has chased them across the yard. We do feed them raw chicken necks as well as other meat and biscuit.

3. We live in semi rural area adjacent to forest and fields and often see our brown hawk/buzzards soaring in the locality. I've never seen any perched nearby but have been conscious in the dry summer that they may be finding it harder to hunt food.

4. Two days ago we found the remains of our lonesome wanderer. She had been pretty much pulled apart and there were feathers in two separate areas of the yard/garden. The dogs automatically became the chief suspects because this seems to be the obvious conclusion but something doesn't feel right about it.

Here's why and I would appreciate any opinions...

If the dogs have killed and eaten the bird - she would have bled out and they would surely have signs of blood and other debris on them?

There were body parts totally missing including the leg and claw and I would have thought they might have eaten the meaty parts first?

They could have eaten the whole bird in one sitting between them, why would they not do that?

I'm prepared to believe it was the dogs but does anyone have any other thoughts about whether I can be more sure it was them and not a hawk? If it was them, are they now more likely to behave in a predatory way??

Thanks in advance

In my experience a hawk will cause a lot of feathers, but in one general area. When a hawk ate my favorite girl, it ate the breast out.

Mabe a hawk got it, and then the dogs riped it apart later. Cause the hawk killed my girl, and left half the body where it laid, and came back the next day.

 

[Chelsa'sChicks]

My dogs run free and my chickens all free range always. No doors . 2 of my 3 dogs are bird dog hunting breeds. They have never killed a chicken and know its a huge no-no. We went over this as puppies.

When my small dog first met my hens he had a crazy light in his eyes and wanted to do nothing but harm them. The more I kept my small dog away from the birds the worse he was and wanted to see them, chase and try to kill.
The first time my small dog met the birds: I heard a hen screaming. I run in to find my hen running very tight circles and my small dog literally biting and hanging onto the hens neck swinging around with her. I'm talking all 4 paws off the ground swinging. I can laugh now, but at the time I was beyond ticked.
We did some interactions and I clarified to that specific dog what he could or could not do. Now he is perfect and it has never happened again. Ps the hen did live without injury.
(My small dog met the chickens as an adult not a puppy btw.)