krishna is a nice and naive person who wanna be closer to his family but Govind, being culprit, keeping his bro away..may be he is the witness of the past?? ho sakta hai.
Govind knew the culprit but he cannot reveal coz no one would forgive him.
If there is a third person in the scene other than two bros..it is easy to reveal him coz that person is not imp in the drama so far. No need of hiding him when Govind knew the truth. Govind is protecting him/himself..the blank/threatening calls, may be, from another witness?? or the baby care person??