I would like to offer some systems thinking ideas to the thread. Many might say that I am over thinking this.
I think that true preventive action is when the information, upon which you base your action, comes from outside of the system. Cascading corrective action to similar areas in the system (organization) to me is still corrective action. When someone brings information into the system from sources outside of the system, then you really have preventive action. Re-applying what you have learned from within the system, to me, is corrective action.
I don't think time sequence has anything to do with the definitions. I think the source of the information upon which you base your action is the more valid basis. Is something unwanted happens within your system, and you fix the unwanted thing (elimiante the cause) and then cascade that to other areas within the system, is still corrective aciton to me.
If understanding and knowledge comes from outside the system, and this understanding and knowledge allows you to eliminate the casue of a potential unwanted thing, then I say that is preventive aciton.
For those that say this is over thinking it, I say that your wrong. What would support bringing new understanding into the system if this is overthinking things?