One of the crew was an instructor at VT-86 when I went through and he briefed the squadron on the whole experience at a squadron only safety standdown. If I remember correctly, they were held by the Italians for a few hours before they were handed back over to the Marines. He was pretty explicit that the Marine COC cut them loose without any help from the beginning to the end, he was understandably a bit bitter with the Marines about the whole experience.
He also said that it was the only accident he ever heard of that did not have a safety investigation. From what I remember, he said that the Safety Center sent someone to Italy and soon after he arrived he had a meeting with a Marine MGEN that told him that he was to turn over all of the results of the investigation to him, for possible use in the JAG and Italian police investigations. The Safety guys refused and eventually left without investigating because the Center did not want to compromise the sanctity of of a safety investigation. HeyJoe might be able to shed more light on that, but he was pretty clear about it.
On a side note, he was one of the best instructors I ever had in my time in flight school.