User blog comment:FairyRaven/Fairy Tail Chapter 397: Steel, Review and Commentary/@comment-25111584-20140826105558/@comment-7418318-20140827073445

On Tenrou Levy already showed that she's not exactly using her mental capabilities fully when in such a dangerous battle, or at least when she's in such a situation without her team. So her messing up in the heat of battle are well within her established character.