RIP database and administrative distance

I was helping a friend study for CCNA the other day and saw a RIP behavior I'd never noticed before. I knew that RIP keeps a local route database that is displayed with the show ip rip database command. If another route to the same prefix with a better administrative distance is preferred in the global routing table, however, the RIP database doesn't show the route. This is different than more sophisticated routing protocols in which a prefix is kept in the protocol-specific topology table even if a route from another protocol with a better AD is in the global routing table.