looks like reflection class newInstance creates in memory representation of code where values are used, so using reference as constructor signature, you can not use this method.
as the same input if called via new, or new $class works, but not via reflection:
class a {
public function __construct(&$a, $c) {
}
}
// this works
$A = new stdClass();
$a = new a($A, 11);
// also this works
$classname = "a";
$a = new $classname($A, 10);
// but this fails:
$r = new ReflectionClass("a");
$r->newInstance($A, 10);
PHP Warning: Parameter 1 to a::__construct() expected to be a reference, value given in reflection.php on line 15
PHP Warning: ReflectionClass::newInstance(): Invocation of a's constructor failed in reflection.php on line 15