It is not end of story.
No phone call from Neville = a guilty Jeremy.
Jeremy had mysteriously turned his answering machine off. Neville mysteriously waited a long time for Jeremy to answer.
What if there was an 'Adam' in the jury asking these questions ?
There not good questions just because you think they are, they're inane and based entirely on unsupported assumptions. If there had been an Adam on the jury I would hope that the other jury members would tell him that his questions are not based on the evidence heard and dismiss out of hand his ridiculous and unsupported assumptions much as we do on here

Take Roch's advice and read Hunter on the ballistics evidence . It is much more informative than whatever it is you have been reading, and based on known facts and evidence rather than supposition and hearsay.