Viewport is the operative word here. The way it is now rotate layer, and rotate layout are actually a rotation of the view, not the layer/ layout.
Think of it as the camera, scrollto is telling the camera to focus on the character, and the arrow keys tell the camera to rotate.
The work around(... well not really a work work around, this is just how it works), is to manually set the scroll.x, and scroll.y in events, and not use the scrollto behavior.