problem with catch all route catching redirects to external websites

We use a catch-all route in SomeController that incorrectly catch
redirects to external websites when we use the 'redirect_to' method.
Any help on how to avoid that is greatly appreciated.

This is our routes:

resources :some_controller, :path => '/' do
collection do
get 'go_to_external'
end
end

This is an action that does a redirect to an external website:

class SomeController < ApplicationController

  def go_to_external
#should not be caught by the some_controller route, but is caught by
it.
    redirect_to "https://example.com", :status => :found

  end
end

Best,
Andy