I'm gonna say something unpopular: I don't like to rush.

[tdb]

How exactly is hurting the entire party, who had nothing to do with the one person pulling, an acceptable response?

Criticize them in chat, kick them if they refuse to stop (assuming the rest of the party is okay with small pulls). Don't force a wipe because you're upset.

I believe the idea is to let the person who pulled extra mobs die to the pack they pulled, and then for the tank to pick up the mobs so the rest of the party can kill them. Or possibly just let the mobs return to their original location, if mobs in dungeons do that.
It does require co-operation from the other players of course; the healer must not heal the disruptive player, and the other dps may have to switch to single-target attacks to avoid getting aggro from the new pack. But if everyone is on board, it's very much possible to do this without wiping the entire party.