Strange Opencart conception about Order Edit

During develop my new extension for OpenCart I noticed one conception about when edit and order from administration panel, but I can’t understand why OC Developers Team have decided to be this way.

I’m familiar with OpenCart but not with everything.

To my surprise I noticed that when edit an order and click on “Continue” button the products are added back to the oc_cart with Ajax and then immediately another request get them from this table.

So may be this conception is applied on other apps, but what is the reason for this?

I want to understand it by competent developers and I’ll be happy if we can discuss the benefits of this. 🙂

Source: stackoverflow-php