Sorry, you are right on the muscle meat thing. I had heard elsewhere that muscle meat were things like gizzards. I apologize.
I realize that bacteria is not the issue, but there is a much higher amount of bacteria in ground food than in whole, and I'd rather start with something easier on a dog's system than ground. Ground doesn't give the stomach muscles much time to know that food is coming, and therefore prepare itself for the food. For a dog who's had raw before I wouldn't hesitate. For a dog who's never had raw before, I'd start out slow or skip the ground until they are more used to raw food. Just my opinion, of course. There's no wrong or right answer here.