Richard Follis, Family solicitor said that there was no doubt that the morphine played a part in the twins' deaths.
He said if the morphine had not been given, probably both twins would be alive today.
More top news
His driving that night has been described by police as "careless" and resulted in a "needless loss of life."
Midlands-based charity RoSPA is encouraging people to share the Firework Code ahead of Bonfire Night and Diwali celebrations.
The Bromsgrove cyclist claimed the former technical director told her to "go have a baby" after her contract was not renewed.