From (p2,id-gate) and (p2,id-ex) we see that a domain creator cannot open a domain it created given a restart key. Here is why.
Imagine that Joe owns a program P of general utility for organizing data. Jack owns a proprietary program A that uses P. Joe suspects that A uses P and would like to know how A works. Joe calls a requestor's key to get a domain obeying A. He passes a meter with a keeper loyal to Joe. When he suspects that that P may be running on A's behalf he causes the meter to expire and gets a restart key to the domain obeying P. Since Joe holds the builder's key to the P factory he can get the domain creator of the P domain and open that domain while it had data that is proprietary to A.