The Royal Marine has been CM'd and now found guilty in a (relatively new to many surprised people) manner that suits the current political, judicial and military zeitgeist - nothing less.
It will be the thin end of the wedge for good people remaining and serving within the military. In the future you can expect your VT, you voice recorders, your head-cams and everything else all to be forced from you in case of when the time arrives and suits a challenger.
I will go as far as to wager (if they don't even already exist) that because of the circumstance in which the vital evidence was gathered and presented in court (the film) - that in the future -independent officer-level lawyers will be likely to be attached to units on operations and one of their tasks will be to gather, record, collate and store all media as evidence (for use in court and that will roll one way or the other). I can see this coming a mile off, and then you will be all totally screwed. Mark my words.
edit to add - to be clear, you will have to work alongside a form of independent modern Commissar charged with holding the media for future use in an independent role in court. The Govt. will drive this upon you whether you like it or not.