The four of them stood behind Erin with slightly shocked looks and they watched silently as Erin told Natasha and Haruto that she felt pity on them and that they were free to go.
Out of everyone, nobody expected Erin to be the first one to feel pity and let these bastards go after everything that they had done. Mako had a completely different train of thought as he was actually going to impose the opposite of what Erin did.
The reason why Mako stopped both the fights and shared with everyone the cruel punishments of El Diablo that everyone feared was that he actually wanted to eliminate those two quickly so that they won't be in critical condition and could be sent home faster rather than spending time in the hospital recovering.