I know again I am in the minority here. However, I feel Sai not accepting her mistake but putting all the onus on Virat is wrong. When Virat does accept his part, why can't Sai. Sai has never accepted her part of the mistakes anytime. She always says (and of course even the forum does that) it's Virats mistake. However Sai has never behaved normally in any of the episodes where they have had confrontations (be it the hand holding episode or the Devkit shaadi). She has always been very arrogant and behaved very irresponsibly. Because whatever said and done it would be Virat who would have gone out to look for Sai if things had not turned out in Sai's favour. I feel she should have been more forthcoming abt her thoughts and actions with Virat atleast since he is the one person who has taken up her responsibility in this world. I am not saying that Sai should have done this out of LOVE towards Virat but rather due to her responsibility towards him and the responsibility (Sai's) he has taken up upon himself.
Sai's mistake is that she doesn't communicate with Virat, but there wouldn't be a show if she did.
Regarding doing what she had to do, she didn't make any mistake. She did what was necessary.
Apologizing though? No. Virat loses the privilege to an apology from Sai as soon as he decided to commit domestic abuse. He should be happy she didn't call the police.