I couldn't find what version of PHP he was testing anywhere on the page. However, the second test ("Using the =&-ref-operator") makes me think he isn't testing

I couldn't find what version of PHP he was testing anywhere on the page. However, the second test ("Using the =&-ref-operator") makes me think he isn't testing PHP 5. This functionality was deprecated and, if error reporting is turned up, will cause an E_STRICT error to be thrown.