I didn't expect it to appear in Case Files especially, as Hawk says, having recently been reprinted with the Aliens story. What I didn't realise until checking now is that it was printed as Predator vs. Dredd and was technically a reprint of the Dark Horse series. Given the very short time lag I assume the intention was always to print it in both places almost simultaneously but, for those who care*, it gets them off the hook in terms of what the Case Files normally contains on two counts.
Interesting about the numbering though. On balance, I think I'd rather have the issues with no stories listed on the cover than a mysterious gap.
* Obviously, I care enough to try and figure out the reasoning behind these things but, ultimately, I don't get worked up about the content.