It's accurate to the degree that the relays I'm checking (about half a dozen of the biggest for the moment) have list events for the given user.

All the list kinds (NIP-51) are replaceable events, so I'm getting all the list events I can from all the relays, then sorting them by created date and referencing only the most recently created.

It's possible (probable, some might say) that I'm missing the most recent list for a given user because it's on a different relay. But as NDK get's better with relay discovery, and I start to implement relay discovery myself this sort of error should go to near zero.