User blog comment:FairyRaven/Fairy Tail Chapter 397: Steel, Review and Commentary/@comment-9468724-20140825223634/@comment-7418318-20140826082120

I've always seen this attack as Mirajane using Elfman as a weapon, rather than Elfman acting on his own. Otherwise there wouldn't have been any reason to even mention her stealing the Macro Curse.

But either way that situation had nothing to do with Nakama power anyway. Even if Elfman acted on his own, it was still a sneak attack, rather than the power of friendship.