$this->models[$key] issue

[Silentscripter]

From your Repository.php:

protected function getModel($key)
    {
        if (!array_key_exists($key, $this->models)) {
            list($namespace, $key) = $this->splitNamespaceAndKey($key);

            $this->models[$key] = Config::query()
                                        ->where(Config::FIELD_NAMESPACE, $namespace)
                                        ->where(Config::FIELD_KEY, $key)
                                        ->first();
/* omissis */

The $key parameter is overriden when splitting namespace and keys. When $this->model[$key] is called, if the orginal key had a namespace it will be ignored thus provoking a possible conflict when two equal keys from different namespaces are used.