URL Routing Issue

[eluser]Unknown[/eluser]
I'm pulling my hair out over this one. I've used CI for a couple projects now and I honestly don't understand why this isn't working. My understanding is that routes work top-down, so if the first one matches it stops there.

If I have this URL,
domain.com/first-person-inside-the-smart-car/1738722217

it always goes to the first route defined below. I can't get it to go to the second route. Has anyone bumped into this issue before? It's driving me crazy and I can't figure out why it doesn't work like I've always known it to.

Code:

$route[':any/:any/(:num)'] = 'video/setPlaylist/$1';
$route[':any/(:num)'] = 'video/setPlaylist/null/$1';