User blog comment:IamJakuhoRaikoben/Chapter 371: Tartarus Arc: Part 2 - Song of the Heavenly Dragon, Review./@comment-4449950-20140216015651/@comment-7418318-20140217123040

I think the same.

Her orders were for Elfman to install the Lacrima in Fairy Tail's guild-hall. And considering how surprised she was about the FT mages surviving and how Elfman would have died in the explosion if not for Cana, it hardly surprising if Sayla didn't put any contingency orders into Elfman's mind.

This is hardly the first time that the Demons arrogantly underestimated the Humans' abilities and overestimated their own infallability.