The evidence test produces a set of mock evidence in the evidence pool of the 'Primary' node. The test then fills the evidence pools of secondaries with half of this mock evidence. Finally, the test waits until the secondary has an evidence pool as full as the primary.
The assertions that are removed here were checking that the primary and secondaries' evidence channels were empty. However, nothing in the test actually ensures that the channels are empty. The test only waits for the secondaries to have received the complete set of evidence, and the secondaries already received half of the evidence at the beginning. It's more than possible that the secondaries can receive the complete set of evidence and not finish reading the duplicate evidence off the channels.