Scenario: A group of 8 players roll through an area, see a lone person gathering or grinding mobs, and kill him to take his stuff. The solo player decides not to fight back. As the system is currently designed, only the person dealing the killing blow is corrupted.
So what happens to the corrupt player in the group? Do they
- just remain in the group as if nothing happened, and the other group members can heal/buff/rez as per usual?
- stay in the group, and can't be healed, rezzed or buffed, but doesn't take damage from offensive abilities by party members?
- stay in the group, but will be damaged by other party members, like any other mob.
- get auto-kicked from the group and is treated like any other monster
All this isn't covered by the wiki, so this post is also about getting your opinions.

I am by default assuming that in option 1-3, they can't join any other non-corrupt group. They are only allowed to stay in the group they were in from the start. However, this also opens up issues if they lose connection or have to relog for any reason. Should they be allowed back into the group if that happens?
In option 1-3, can the other group members earn shared xp to remove the corruption status of the single player, as long as the corrupted player is within XP radius?
If option 4 is what happens, can the corrupt player group up with other corrupt players? Or are they forever alone while in a corrupted state?
If 2+ corrupted players can group up to grind XP, what happens when one of the two players is no longer corrupt, but the other still is? (options 1-4 all over again).
My personal take on this is, going with option 4 is the simpler solution to design, but it also really sucks in some ways. If you are rolling along with a group of friends and want to contest a grinding spot, it effectively kills your group if the opposing team doesn't flag up, and only 3 of people in the group get the killing blows. Now you just have a group of 5 non-corrupted and 3 corrupted players outside the group, and it's just a big, sucky mess for everyone involved.
My Preference
If they stick to their current design, where only the player doing the killing blow become corrupt, I think the best solution is option 1.
My preferred solution is a little different. I think if any group member kills a green player, the ENTIRE group (within a radius) should get corrupt, with one big exception.
From the wiki:
Players will be able to opt-in (via a checkbox) to allow their beneficial or non-beneficial AoEs to hit flagged players. If this is checked then AoE heals or damage will affect flagged players. If it is not checked then the AoE will not damage or heal any flagged players, and as such will not cause the caster to be flagged themselves (if they are not already)
So players who don't opt-in to this won't get corrupted, but they also can't help in the fight.
In practical terms, this means you opt in when running with your usual crew and decide that pvp and corruption is on the table for all involved. If grouping with randoms, you don't opt in, and you are thus protected from the actions of Psycho McStabyerface, who just live for that shit.
For raids, I still think it should be group based. So only the people in the specific group in the raid get corruption, not the entire raid.