Mr. Bajaj can't show emotions, if you are looking for change in expressions, he can't do that because right now he is an emotionless, ruthless businessman. He was pretty good in anger mode. KSG is "muttering" his dialogues and BG score is high pitched, that's why some people are having problems understanding his dialogues, I personally didn't have a problem understand it.
I had problem understanding Erica's dialogues, didn't notice her expressions. Do you think Parth is a good actor? Didn't impress me