So Liz walks in, sees the bugs, and assumes a whole basket of ideas leading to "America is trying to destroy our crops." It seems to me that there could be many many possibilities. I understand being paranoid as a spy and erring on the side of caution but they didn't seem to even consider the possibility of a benign explanation for a second. They've been meticulous in their vetting of situations and always very careful. This time the evidence all seemed to come after the declaration of guilt instead of the other way around.

This kind of character behavior seems like a bad writing clue that means that they will indeed eventually find out that it was never an attack at all and a giant misunderstanding that further challenges their resolve. Its a cool idea but a small misstep in the setup. Another rare hiccup in a well made show.