What is this oven thing that you speak of?
The prep of the bird sounds very close to what I do. I normally use a compound butter with fresh herbs in it to put under the skin.
I normally cook mine in my Big Green Egg. Our oven is usually full of different casseroles, etc.
When the breast is at 161 as directed what is the dark meat temperature? I've found that the dark meat generally lags the breast so I would think that the dark meat would be undercooked. But, I haven't tried cooking the bird this way.