As opposed to non-transactional writes, when a multi-statement transaction throws a writeConflict, we don't increment the writeConflicts counter in serverStatus. This can be confusing for end users since driver automatically retries transactions on writeConflicts (imagine a user sees writeConflictExceptions in a transaction being logged or even popped up to application when driver exhausts retry, but then finds out that the writeConflict counter is not updated).