Too much force was applied when that person hold the kid. Even if the kid has the tendency to get bruised easily, a normal hold will not leave bruises. I have a hyperactive 2-year old son that I have to contain forcefully but he got no bruises, only when he bumped into hard objects. Please make sure that the person taking care of your child is not hurting the child when you're not around.
Too much force was applied when that person held the arm of the kid. A normal hold will not leave a bruise even if the kid has the tendency to be bruised easily. You should ensure that the person taking care of your child is not hurting the kid when you're not around.
Something to pay attention to. Not normal @ all. Please keep a watch-full eye.