A responsibility links an actor to a task.
The role is only the actor’s responsibility when this actor is a Human or an Organization and the Handbook restricts « Role » to human or organizational responsibilities. The red association is redundant to the one with Actor, but aims at expressing this idea (in a true class diagram you would have to use OCL to express this specificity).
It is true that we talk about Roles requirements as a special case of Responsibility requirements, but you cannot define a role without a responsibility (and vice versa).
The remaining part of the diagram addresses the fact that an actor can be Human, Component, etc.
From correspondence with Jean-Michel Bruel: