The way I look at it is that the system must continue to meet its requirements (whatever they might be) whether it gets one GET request or many in response to a single action within the user agent (clicking a link, submitting a form, script making a request, etc.). In general, logging two requests instead of one does not violate any requirements and in fact logging every request, even duplicates, is the expected behavior. Adding the same item to a list twice in response to a single UI interaction, on the other hand, would not give the desired effect.