Principle of Liability

If a manager sees that a contractor is working unsafely and he fails to do something about it, and the contractor is killed, can the manager be found guilty of culpable homicide?

Companies can be found guilty of culpable homicide if they contravened legislation?

Can employees who are injured at work choose whether they want to claim compensation in terms of the COID Act or sue their employer?

Would employees be able to sue the employer if the employer was grossly negligent in causing the injury?