I think OpenAI likes the attention and did not try particularly hard to constrain the setup, even when it went off the rails. Also, the whole point is to see how good the models are at exploiting stuff when unconstrained. Turns out: quite good, as expected.
Let me restate what I said in the other thread: Would this have happened if the instructions explicitly said to stay within the sandbox and that all of the (ExploitGym) solutions would be invalid if the system used information or tools from outside the sandbox?
It seems fairly probable that such instructions were not in place.