I'm not an OCUK fanboy, but I think the reality of the situation needs to be brought forward about this queue system. I'm a developer, with lots of web experience, too. Some things which people need to understand is that the 'unofficial queue' tracker is a basic python script uploaded onto a website running a virtual terminal. No one is liable when uploading data. However, OCUK are when developing their own system. The first matter: How complex is the order system? Seeing as the database is MySQL, what SQL queries are needed to first order customers, per card, per ETA, take away cancellations on updates, joining tables etc. You see? It's gets pretty complex, especially when security is paramount.
If OCUK released this queue system that started spitting out users full names, addresses and payment information due to that users relationship with the order number, then I'm sure people would be pretty angry. There is a reason people kept putting in their order numbers into the unofficial tracker without the last xx at the end, and that is privacy. OCUK do not want your details being leaked, breaching confidentiality which brings in the data protection act not to mention the ICO breathing down their ass for lack of planning and proper security implementation. Slapping some code together is the easy part. The hard part is IT governance and following internal and external policies for the safety of everyone's information.
However, why they didn't just mention something similar to this, I've no idea. My only speculation could be that they aren't doing any of that, and could be going old fashioned printing out a bunch of orders and firing them into MS Excel and simply using functions to calculate the first come first serve. Or, I'm completely wrong, and they're just really busy and don't have the time to explain it to marketing and CS. Every company has their own way of doing things, and my theory could be way off. I do think communication could be better from them, though. I think that is where people seem to be getting most angry. Sometimes Marketing/PR or even legal will stay quiet, since it's sometimes seen as the best option during botched launches like this where you might just keep digging yourself deeper.