If the route is not found, then phalcon uses default controller. So the only way to detect route not found error is to do smth like this:
$router->setDefaultController('SomeNonExistController');
I was thinking in adding a special route to the router to be used when none of the configured routes are matched. Somewhat like:
$router->fallback(array(
'controller' => 'index',
'action' => 'notFound'
));
This is also my concern.
Here is an explanation for this: https://forum.phalcon.io/discussion/106/difference-between-setdefaults-and-notfound#C442