If a member of the Exam Development Committee wanted to use an item they wrote for the exam for another effort, are they allowed to do so? My first thought was no, but I thought I would check with you. Maybe if they revise the answer or question in some way?

Those items are the intellectual property of your certification body, and shouldn’t be used for any other purpose.
Exposure is the bane of item pools. Items that become in any way ‘public’ should not be used on the exam.