I think we're talking at cross-purposes. I'm just saying that because it's underspecified, the Zend engine can be both accurate to what's in the PHP manual, and to what's in the spec.
Anyway, it's a slightly pedantic point, so I'm probably not contributing much to the conversation here :)
I understand your point. The spec as written means the Zend Engine itself is accurate the spec. The problem is the spec isn't accurate to the language, as it exists, in the wild. Existing correct and valid PHP code executed to this spec will behave incorrectly. Therefore, it's not really a PHP spec.
Anyway, it's a slightly pedantic point, so I'm probably not contributing much to the conversation here :)