Just nonstop record like the rest of us, wait a week or two and delete the recording of the previous week.
As much as I'd love the party rules to be specified a little bit more, I think you may be asking a bit too much-In addition to this, there is a time limit-it's within the life of the player in question.
For example: Player Alex damages Player Brian in a raid. Player Brian kills Player Alex during the raid. Now the situation is over and Brians party members cannot hunt Player Alex down for "damaging a party member" (Or Damaging Player Brian who is in their party for you slow people).
Essentially you can prove that it was not rdm/it was rdm very easily. Depending on whether logs reset or not. Which is an issue on itself what with people abusing the party system and shooting their friends filling up damage logs.
^I think this suggestion is fine, but also I would like to point out that we need stricter rules for players doing this because it happens frequently.
Neutral
At least until I hear from someone smarter than I am.