There might be a chance that a technicality was used where the judge had to instruct the jury to deliver their verdict but it was not made clear, which is a shame. I hope that David finds a solicitor and sues Gary in a private law suit, he should have grounds based on his medical records and I believe that the fact he threw the first punch might reduce Gary's sentence but he would get punished, especially as he is on probabation. Don't think I have ever seen this done in a soap, apart from Cilla threatening Rita with a compensation claim, but that was a con.