OK, well, the continue shopping button on the cart page does not post to the results page.
when the add to cart button is pressed, the page that contains the add to cart button is stored in a session
On the cart page, the continue shopping button triggers a behavior to go back to the last page that an add to cart button was used on.
there is no way ion the results page to know if the continue shopping was pressed. you can check for the cart not being empty, but you cannot check for the continue shopping button pressed on the results page.