-Covid cleared
-Oxygen level improved to 95%
-Awake and able to do minimal activities

Sorry for your loss, but as I see it, there is no more reason for the doctor to keep him in UNICU.

As you know with the current covid and influenza outbreak gov hospitals are overloaded and they have to prioritise those that really need beds in critical wards.

Life and death is unpredictable.

You can try sue the doctor for negligence, but for what? To get revenge on the doctor?