Doubt in conflicting version behavior

[DavidTurner]

If there are multiple operations on a single document in a bulk request then these are processed in order. There is no ordering guarantee across operations on separate documents. See here:

Order of _bulk request operations

You can rely on the fact that operations on the same document (same _index, _type and _id) will be in order. However you can't assume anything for documents that have different indices/types/ids.