I don't think the role of Aruba (the Italian ISP involved) was the one of the innocent third-party ISP. IANAL, but as far as I know, there is no "secret court" that can ask them to do that.

They did it not because of a break (or so I understand, I'll be happy to be mistaken) but, probably, "to keep the Man quiet". While understandable (to a point) this is definitely not what an "innocent third party" will do.