It seems like the seniors can't stand Lee Kang-in's line

When they see juniors who aren't serious during training
and are just fooling around,
the corporals and sergeants
want to say something because they're frustrated,
but they're holding back because they're told it's "unfair treatment."
Meanwhile, the officers who are supposed to mediate are just standing by because they're foreigners,
and the seniors in the middle are so frustrated they're thinking,
"Fine, I'm done with this crap."
I feel like it's a situation somewhat like that.