Suppose there is a train moving to the right. and inside the train there is an observer, A. Outside the track, there is another observer B. When the train passes in front of B, right at the instant when both the ends of the train are equidistant from B, two lightnings strike the two ends. Now, to A it would appear that one of the lightning hit before the other. Now suppose, that there are devices at the ends of the two trains, which either let a current flow through a particular circuit or it doesn't depending on whether the lightnings hit its ends simultaneously. And the mechanism (on how this device works) is out there for both observers A and B to see. So will A observe a current and B will not, or will both A and B observe a current flowing through them? Assume that current flows if lightning does not hit both ends simultaneously. Since the mechanism is out there for any observer to see, it would appear that if both ends are hit simultaneously to one observer, there shouldn't be any current observed by that observer, right? Or else the laws of physics will seem to be not working properly for that observer or so I think.