Addressing a forum thread about people inadvertently flagging for PvP when cross-realm grouping, Bashiok mentions a welcome change for Warlords of Draenor that I hadn't heard before -- namely, a more robust PvP toggle on/off that will prevent issues like that from occuring.
Bashiok - Re: Stop..ramming..pvp...down...my...throat!!!
Well, I understand where you're coming from, but flagging as a PvE character is based on a player's action to flag themselves (even if it's on accident), so I'm not sure it's us making you PvP. The systems that can cause someone to flag can absolutely at times be involuntary, which is notably frustrating.
In any case we are continuing toward a goal of a PvP on/off toggle for players on PvE realms to be added in Warlords of Draenor, which would absolutely and in all situations allow someone to refrain from becoming flagged regardless of their actions. Heals toward flagged players would fail, coalescing to PvP realms wouldn't be possible, misclicks and AoE's would never damage a flagged opponent, etc. It's actually quite a bit of work because of all the systems involved, but it's still something we think PvE players should have, and how the game should work for them.
I admit I especially like the idea that misclicks and such would never damage a flagged player, thus preventing a host of shenanigans I've seen over the years (mounted flagged players crowding on top of quest givers, stealthed players jumping while flagged in front of melee characters in order to get them to flag so that their friends can kill them, you know the ones I mean) and would put the decision to PvP squarely in the hands of the player in question.
I for one am excited for this. Keeping PvE-focused players able to absolutely refrain from PvP is fundamental to player enjoyment on both sides of the PvE/PvP debate, in my opinion.