We once learned a good lesson about this, as well as recognizing the real threat that ESD poses. We once had a terrible failure that was the result of a main signaling line being damaged by ESD such that it had much higher resistance than it should have. Our signal levels were too close such that it danced over the line a few times and got interpreted as the opposite value, but only sometimes. It also taught a good lesson that when the robots do become self-aware and take over the world, it's gonna hurt like hell.