That was my first thought when I heard the first reports. Now that this report mentions a "contractor who does maintenance at the laboratory", I have to wonder if the person is Mexican.
Either way, any bets on whether the person is a legal resident of the US?
A contractor who does maintenance at the lab: IOW, the lab outsources custodial services. My guess is the custodian was emptying waste paper baskets or the recycling bin and goes, "whoa!!! Whaz' this?" So if this is the case, who's really at fault? Unlocked file cabinet? Jammed paper shredder?