>...But passengers aboard the sailboat say the lights in the cabin were on, and Weber told investigators he was
certain he'd turned on the running lights and left them on.

However, a crucial light for avoiding the collision would have been in the stern, or rear, of the 27-foot sailboat.<

On my old monohull, it has a weak stern light(Perko) that can only been seen well within a 60+- degree angle shooting back,
so a witness on shore could be out of range(angle) of the stern light.
Also cabin lights illuminate a sailboat 1000% more light than a stern light. The Defense could concentrate more on cabin lights.