User blog comment:IamJakuhoRaikoben/Chapter 459 & 460: Weakness & The Alighted Pegasus, Review./@comment-184.178.44.233-20151102013204/@comment-7418318-20151102075319

While it wasn't stated, I strongly suspect that the barrier was a conditional one that only hindered enemies, but let allies through.

Almost all barriers we've seen Freed create had conditions to them, either for walking through or for dispelling them after the consitions are met. "Only statues and 80+ year old people are blocked", "Only the winner may pass", "Only our Tenrou Team can pass" and so on.

After all the Dragon Slayers, Exceeds and Erza were fighting outside the barrier, which means they must have gone through it.

Could this be how Brandish got through the barrier? If the barrier was triggered by hostile intent against FT, Brandish and Marin would probably not have been blocked due to their original reasons for being there. Brandish didn't really want to attack Fairy Tail, but just visit Lucy and find out why she looks so familiar and Marin was just puppy-following his mistress instead of thinking about fighting, so no hostile intent from him either.