i see what you are saying but here is the difference:
is a short-lived, typically stateless object used to perform initialization or to invoke methods in another
You are thinking the Event is the "short-lived" object, and yes it is. However, the Event object is not what invokes other methods. It is a data object pushed to the invoked method. Small difference and easy to oversee, but what makes all the difference. The invoker is registered method in the EventDispatcher collection. A not so "short-lived" object.
hope that helps. cheers