With the 7 ladies joining the scene once the explosion shook the ground, they ran in without even waiting for any type of permission. The ground shaking was their permission which made them break the deal, what if their Grand Leader was blown to bits? What if the three need help fighting demons?
Staying all the way back to the entrance wont help them figure out whats going on in any way, they had to intervene. But it wasn't no trouble, because as Eric crossed the second section half way to invite them down here.
He felt more than happy to save Bittore's life even though he was smacked in order to help, and to have 7 pairs of hands helping settle everything down is indeed more than they asked.
