In vanilla WoW it was possible to get ravenholdt to exalted and also get syndicate to 2999/3000 into neutral simultaneously if you have someone in your party kill the ravenholdt npcs and you don’t help. In the current state of classic, we have a change from 2.2.0 that makes this impossible.
In patch 2.2.0 this was changed (from the patch notes).
• If you get a positive reputation from combat you also get the corresponding opposite reputation reduction.
I have tested this with friends and verified that you receive both the positive and negative reputation increases which shouldn’t happen. What this means for rep grinders like me is that it’s impossible to raise up both centaur clan reputations to honored (the max) at the same time.
Additionally, wow gamepedia historical edits from 2010 seem to suggest that this was possible in earlier builds of WoW.
In earlier builds, a player could become friendly or higher with both Centaur clans at the same time, by having someone else in a party kill a member of the Gelkis or Magram, which would cause the player to gain reputation with one Centaur clan, while not losing reputation with the other. As of patch 2.2 the player will gain and lose reputation regardless of who in the party actually does the killing.
Hopefully Blizzard sees this and fixes it!