So the alleged acts are horrendous. Not that allegations being made are horrendous. Wasn't sure from the OP.
Could the documentary scupper the chances of a succesful prosecution - in that all the media coverage/social meda coverage etc could kill any chance of a 'fair' trial.
It's a bit of an odd situation - given that 2 of the allegations that are the more 'solid' and have fairly damning evidence occured in the US - could those incidents be used in a British court as evidence? Can the evidence of anonymous people be used in court?