Firstly, this is not the right place to post this, let alone the forums as a whole.
This firing of words should have been reported in-game (right click Report on player or use Report feature), where it will be sent to Jagex for review. Evidence recorded on your own (or by any other means) are not valid.
3. Don't target specific players with accusations.
This means naming and shaming players in the forums which we do not permit. Again, reporting in-game is the way out. Nothing can be done in the forums, sadly.
Please use the advice as above if you encounter any other troublemakers.