If "Payment Method" checkout pane disabled, payment process is not triggered

Spotted this myself just now when trying to hide the "Payment Methods" pane - with only one method enabled, it's better to omit it from display.

But ... clicking "Submit Order" (or was it "Review Order" at the cart screen?) bounced me straight to the post-checkout URL without a warning message, and triggered the purchase confirmation email (via "Customer completes checkout").

Hiding the payment methods screen should not prevent the user being redirected to