No particular order is a lie - it's in order of most dramatic effect/suspense.
If it was truly random, the call out would look a bit 'odd', but it's always announced in what seems like a neatly gift wrapped box.
They tend to only leave two of the top half of the leaderboard in the 'second half' of the results, because it would be a bit obvious to have Jeremy, Carol and Kirsty all be called in the first half, leaving Ainsley and Jamelia with Peter, Helen, Jay, Kellie and Georgia.
Of course there could be a shock result, but shock results don't come around often, so most weeks the call out is entirely predictable. I'm not saying I could guess every name in exact order, but like I said, from the top half of the leaderboard, 75% of them are likely to be called in the first half. If it was truly random, you wouldn't get those lingering at the bottom being called out last every week.