(mongodb >=2.1.0)
MongoDB\Driver\Exception\BulkWriteCommandException::getPartialResult — Returns the result of any successful write operations
This function has no parameters.
   Returns a MongoDB\Driver\BulkWriteCommandResult
   reporting the result of any successful operations that were performed before
   the error was encountered. The return value will be null if it cannot be
   determined that at least one write was successfully performed (and
   acknowledged).
  
Example #1 Partial result if at least one write is successful
<?php
$manager = new MongoDB\Driver\Manager;
$bulk = new MongoDB\Driver\BulkWriteCommand;
$bulk->deleteMany('db.coll', []);
$bulk->insertOne('db.coll', ['_id' => 1]);
$bulk->insertOne('db.coll', ['_id' => 1]);
try {
    $result = $manager->executeBulkWriteCommand($bulk);
} catch (MongoDB\Driver\Exception\BulkWriteCommandException $e) {
    $result = $e->getPartialResult();
}
var_dump($result?->getInsertedCount());
?>The above example will output:
int(1)
Example #2 No partial result if no writes are successful
<?php
$manager = new MongoDB\Driver\Manager;
$bulk = new MongoDB\Driver\BulkWriteCommand;
$bulk->deleteMany('db.coll', []);
$bulk->insertOne('db.coll', ['_id' => 1]);
$manager->executeBulkWriteCommand($bulk);
$bulk = new MongoDB\Driver\BulkWriteCommand;
$bulk->insertOne('db.coll', ['_id' => 1]);
try {
    $result = $manager->executeBulkWriteCommand($bulk);
} catch (MongoDB\Driver\Exception\BulkWriteCommandException $e) {
    $result = $e->getPartialResult();
}
var_dump($result?->getInsertedCount());
?>The above example will output:
NULL
