I'm not really sure but a person can change the will as long as the nominee (to whom the property is transferred) is not in a position to take it's possession...once the property was taken over by the nominee then the will cannot be changed...
in our case...if daju has left the property to shivani's husband...then as long as that position of husband remains vacant daju can change the will...once it's filled with raghu or Abhi then daju totally loose control over his property and cannot change the will...
so I don't think daju has writeen the property to Abhi...he might left it the "husband" that alone can give scope to shivani to bring in Raghu...in that position...
ofcourse the cv's has such shap turns in store...can't even predict their route...