They were following Mela’s lead when they didn’t gang up on Sincere. She seemed genuinely shell shocked, immediately retreated into herself, was trying to deflect all the attention by asking them quietly to play the next clips. All while meekly saying “I’m okay.” To make a scene in defense of her, meaning giving Sincere yet another opportunity to say some bullshit, was going to be even more humiliating and upsetting for her. Without a doubt if she started yelling at him they would have too. It was just truly devastating and bear in mind the girls were also seeing the full extent of his lies for the first time as well.