An example of how I'm trying to verify that sometimes() is called twice using Laravel's testing stuff

gistfile1.php

<?php
class ValidatableModelTest extends TestCase {
  
	public $validatable_model;
	
	public function setUp() {
	$this->validatable_model = new ValidatableModel;
	}
	
	/**
	 * Utility method to get valid sometimes rules which are used in multiple tests
	 */
	protected function getValidSometimesRules() {
		return array(
			array('first_name', 'min:4', function($input) {  return $input->name != 'Joe'; } ), 
			array('last_name', 'min:4', function($input) {  return $input->name != 'Smo'; } )
		);
	
	}
  
	/**
	*  If we set sometimes rules on our validatable model,
	* when we call validate() on that model we need to make sure
	* that sometimes() is called on the validator object
	*/
	public function testSometimesIsInvoked() {
	
		$this->validatable_model->setSometimesRules($this->getValidSometimesRules());
		
		$mocked_validator = Mockery::mock();
		$mocked_validator->shouldReceive('sometimes')->atLeast()->times(2);
		$mocked_validator->shouldReceive('fails')->once()->andReturn(false);
		
		Validator::shouldReceive('make')->once()->andReturn($mocked_validator);
		
		$this->assertTrue($this->validatable_model->validate(array('first_name' => 'Hello', 'last_name' => 'Mate')));
	
	}
}

My ValidatableModel is not calling sometimes() twice, yet this test passes silently with no complaints? Am I doing it wrong?!