Who rooted Traceback: can you explain this?

Maybe there is more than one way, but:
In Traceback the final stage, where you gain root, in that folder are several files. Can anyone explain why it only works with the first?

From what I can read in the manual of that service we exploit, all files in that directory should be executed, or am I interpreting this wrong?
However I only seem to be able to achieve any result by using the first one… I spend some time in the box trying to find out why that may be. And unless I got very unlucky with the short reset times, I have no idea why this is.

Does anyone know where it is configured that only the first file is used (and then why recover all of them from the backups?)? Or did I just had poor luck with the timing? Currently it doesn’t make any sense and I suspect if things don’t work as I expect, I’m missing parts of understanding it, which makes me a bit nervous… Any help is appreciated.

I found it worked on all of them and as far as I can tell, they are all executed. I’d strongly advise anyone working on the free boxes to use one at random to reduce the risk someone else breaks their attack.