> what and why did it access the information?

Honestly it's very likely something stupidly simple.

"What is the rate of health incident $X in $Y to the $Z degree". The bot went around playing mad libs with XYZ and found that the public AU data wasn't sufficient to get the answer the grader wanted so started kicking down doors.

I saw someone explain it like "A group of masked men rush a nuclear facility, breach security successfully, then count how many buttons are on each control panel on average". Like using a godhammer to destroy a mouse, their motivations and capabilities just fall in a completely different alignment to humans.