refine_collection_shard_key_basic.js checks if entries associated with refineCollectionShardKey are correctly inserted into the changelog.
In the case that the primary stepdown do to a failure, it is not guaranteed that these entries are committed on the changelog.
In particular for every refineCollectionShardKey operation it could be possible to have:

• one or more `refineCollectionShardKey.start` entry in the changelog SERVER-43201
• one or zero `refineCollectionShardKey.end` entry in the changelog. SERVER-44099

Unfortunately the two implemented solution failed to address the problem.

The bug was introduced by:
https://github.com/mongodb/mongo/commit/76208a78621cfe67d417a5781f9202580f1b2608