I have a question about the creation of customer orders. It seems that checkout_process.php calls $order->create(); to create the order. My question is: Is the order created solely through checkout_process.php or is it ever created through a payment module or another module?

I'm asking because I see no other way of capturing the order_id other than using an observer and listening for NOTIFY_CHECKOUT_PROCESS_AFTER_ORDER_CREATE_ADD_PRODUCTS then using $_SESSION['order_number_created'] which is only supplied in checkout_process.php.