Today's scene was not meant to be emotional, it was way to break the ice between them and tone down the anger.
Sona's accident was fatal and it was the time to explore an emotional side of Dev. Dev during Sona's accident was never seen before.
Now the things are different. 7 years' baggage is there. Both have lot of complaints against each other.
Sona has matured so much that she has just learnt to deal with a difficult situation without getthing over emotional.
Dev on other hand has developed a very skewed vision. Sona leaving him and going has wounded him so terribly that he cannot take care and love as a normal emotion. All he knows is pain and hurt.