Wrongful death doesn’t have the same prongs of substantiation that negligence has.
Negligence is a dereliction of duty. If there is no duty, there cannot be a dereliction.
By asking her to leave, he well may have met his standard to take reasonable measures to avoid her injury. By choosing not to leave, she may well have waived his duty to her.
A duty is not presumed to exist nor does it survive any and all attempts to circumvent it.
Let us use a real life example. Two individuals get into a verbal confrontation over the perceived driving skills of one of the individuals. They speak verbally and one of the individuals repeatedly moves away from the other individual. At a point in the confrontation, one individual slaps an object out of the hand of the other individual (the individual who had been moving away from him). The slapped individual immediately punches the slapper in the jaw, the punched person strikes their head on the pavement and sustains a brain injury that leads to their permanent incapacitation.
The person who punched had a duty not to injure the other individual until the moment that the individual struck him. At that point, the duty to that person ended by the actions of the person who ended up injured. The injured party knew that their action could incite the reaction from the striker.
A jury held that the striker was not liable for the injury to the other individual because he did not have a duty to breach at the moment he struck him, and a breach of duty is required for a negligence claim.