Gibson provided two accounts and so would never survive cross-examination in court.... Well, you're the solicitor, but I just assume that's pretty much the death knell of any testimony.
I will have to get back to you on all this in a few days time.
Someone, some years ago on here provided an excellent analysis of Gibson's 2 accounts and their timings. It might have been Paul Slish. One of Gibson's accounts is that Stone had reported 5 rockets seen to Captain Lord via the speaking tube. This was Stone's second speaking tube conversation with Captain Lord.