> The question is not of technical difficulty though, most hacks are trivial or within reasonable limits for most motivated solo actors
Not exactly my point. My guess is that the system is so brittle that it was probably hard not to hack.
Agents see websites differently to humans. If its goal was to, say "get medical stats" and it saw that it had a choice of 10 requests to make, and one or two of those happened to be unclearly illegal but useful to its goal, it would have gone for it anyway just as I likely would have if given the same choice without firmly knowing it was illegal.
Having said that, it could have been some clearly malicious hack that was performed and I'm not sure why it would have to write any files. We'll likely never know what happened.