According to the suit filed on Friday, Gordon left the bedroom wearing different clothes than he was wearing while arguing with Bobbi Kristina minutes before, got into bed, laid his head on a female house guest's body and said, "Now I want a pretty little white girl like you."
Hargrove's alleges another guest at the home went in to check on Brown minutes later on January 31 and found her face down and unresponsive in the bathtub with her mouth swollen and a tooth hanging loose.
Gordon allegedly rushed into the bathroom and began efforts to bring his girlfriend back to life.
Paramedics were called to the home and Brown was taken to North Fulton Hospital, where she was revived and placed in a medically-induced coma. She was later diagnosed with irreversible brain damage.
Amending her complaint on Friday, the conservator wrote: "I am deeply saddened by the recent death of Bobbi Kristina Brown. I extend my sincerest condolences to all of her family.
"Consistent with and to the letter of the civil action I initially filed on behalf of Bobbi Kristina, we will continue to pursue justice for her. I have filed today an amended complaint against Nicholas Gordon adding a count for wrongful death and for pain and suffering. We will leave no stone unturned in seeking justice for Bobbi Kristina Brown."
The suit also suggests several witnesses saw Gordon punch Brown during another row days before the drowning incident, with at least one bystander confessing that Gordon continued to attack Brown after she fell to the floor, "hitting her in the face until she was bloody" and then kicking her in the side.
Brown's tooth was allegedly knocked out in the attack, after which Gordon dragged his girlfriend up the stairs by her her hair, according to the complaint.
The lawsuit asks for damages of at least $US10 million each for the assault, battery, intentional infliction of emotional distress, and conversion.
- WENN