"extending" with Decorator pattern - property values

[bkdotcom]

Attempting to create a decorator/wrapper that adds logging

<?php

class OAuthWrapper extends \OAuth
{
    public function __construct(\OAuth $oauth)
    {
        $oauth->enableDebug();
        $this->oauth = $oauth;
        $this->debug = &$this->oauth->debug;   // this line, it does nothing
        echo 'construct: ' . \json_encode($this->oauth->debug) . ' ' . \json_encode($this->debug) . "\n";
    }

    // ...
}

$oauth new \OAuth(self::$consumerKey, self::$consumerSecret);
@oauth2 = new \OAuthWrapper($oauth);

Outputs

construct: true false

I would expect "true true"

Why is this->debug false?

Is the OAuth extension implemented in such a way that this is not possible?