ian0mackenzie on "remove_action on a method: Why didn't this work?"

I hope this is the right place to post this - if not, please just simply direct me to the right place!

I recently came across a plugin that, among other things, added a meta entry to the header. I needed to remove this action. The add_action entry looked like this:

add_action( 'wp_head', array( &$this, 'addMetaData' ) );

"this" is in relation to the class, called Vc_Base.

My initial reaction was to add the following to my functions.php:

function removeAddMetaData() {
	$vc = new Vc_Base();
	remove_action('wp_head', array(&$vc, 'addMetaData'),10000);
}
add_action('init', 'removeAddMetaData', 10000);

This did not work. I also tried changing 10000 to other values.

What DID end up working was this:

function removeAddMetaData() {
	remove_action('wp_head', array(visual_composer(), 'addMetaData'));
}
add_action('init', 'removeAddMetaData');

I tracked down visual_composer() and it only has one line:
return vc_manager()->vc();

I tracked down vc_manager()->vc() and, among a few other things, it contains these lines:

$vc = new Vc_Base();
$this->factory['vc'] = $vc;
return $this->factory['vc'];

So, if that's just doing what I did (in a round-about way), why didn't my initial idea work? I'd really appreciate some feedback since I feel I'll understand WordPress/PHP a whole lot more if I can understand this!

Thanks in advance.