Let me start with the reason why Arnav didnt react or move when Shyam blamed the whole thing on Khushi and accused her of being the evil one in this house. You can even ask why when both NK and Akash became angry when Shyam accused Khushi than why didn't Arnav move a muscle? Arnav didn't have to do anything at all at that point - he knows that no one will believe Shyam. Arnav also had the faith in his sister and he was counting on her to take care of Shyam. Arnav grew up with his sister and knows her inside out - he knew the second she ripped the Mangalsutra from her neck that Shyam cannot and will not be able to win over Anjali again. Khushi on the other hand doesn't know Anjali that much - she has only seen her as a sister who took care of her brother and as a devoted wife who worshipped her husband. Khushi has never seen Anjali as a betrayed woman who will now never ever believe Shyam - that is why Khushi went to Anjali and tried to make her ignore Shyam's plea. Arnav behaved like a man who loves and trusts his wife completely and more importantly he knew Khushi can take care of herself in any situation. NK and Akash behaved like a brother and friend who were ready to beat up any man who dares to insult their friend/sister.
Now moving on to the fact that some members are calling Anjali selfish because she hasn't apologized to Arnav and Khushi for everything Shyam put them through. Why should Anjali apologize? She was not the one to lust after Khushi nor tried to kill Khushi and Arnav - it was only Shyam who is responsible for all of that. Anjali's only fault was that she loved and trusted her husband over anyone else and she paid the ultimate price when she lost her baby. Anjali at the moment is only focusing over the fact that her husband is evil and that he killed their baby for money - she hasn't had time to calm down and also realised that the whole Arnav kidnapping thing was true and that Khushi has been through a lot as well. When she does that I can almost guarantee that Anjali will apologize to Khushi sincerely and also a heartfelt one to her brother - for not believing him thus leading him to almost lose his life and Khushi's life.
What I am also trying to say is that the day is not over yet - we have only seen Anjali's rage in yesterday's episode. In today's episode we might see a sad Anjali who asks her brother to tell her every single horrible deed her husband did and than she will ask for forgiveness. So I am humbly asking members to just relax and wait before jumping to conclusions because we might be proven wrong.