You might be surprised. What I observed during that time was that a lot of, if not most, senior people were clueless about what computers were actually doing. The potential "reach" of that intern might just not have occurred to people.
And we still have national security / diplomacy disasters resulting from relatively low level people having access to vital computer systems beyond anybody's imagination.
I wonder if he had a supervisor sysadmin that he was working under, but given how he described his boss, that seems unlikely as well.