This test restarts all of the nodes in the replica set around the same time. This means that all three nodes can lose their data when running on the inMemory storage engine. Depending on the timing, all three nodes can end up trying to initial sync from one another. Eventually they fassert() because they cannot find a sync source.

This test should be tagged "requires_persistence" to prevent it from running with the inMemory storage engine. Thanks to judah.schvimer@mongodb.com for helping me understand the problem!