OK. The resolution of paradox is due to what is known as the relativity of simultaneity. I will talk about this in two stages, firstly I will say what it is and how it resolves the paradox. This is where many explanations stop because the student is expected to know about the relativity of simultaneity. Then, if you wish, I can show you how it arises the from basic postulates of special relativity.The relativity of simultaneity is a basic result of Einstein's special theory of relativity and it says that spatially separated events that are simultaneous in on frame of reference may not be simultaneous in a frame relative motion.We set up the doors to open simultaneously in the garage frame. That means that, in general, they will not be simultaneous in a frame that is in motion with respect to the garage. In particular, the doors will not close simultaneously in the ladder frame. In fact, the back door closes first first (and then immediately opens) just as the front end of the ladder is about to hit it. Later, in the ladder frame, just as the back end of the ladder has passed through it , the front door of the garage closes.Note that these two things, the front door closing as the back end of the ladder passes it and the back door closing just as the front end of the ladder is about to hit it , both also happen in the garage frame. The difference is that in the garage frame they are simultaneous and in the ladder frame they are not.The result is that the ladder passes through the door in both reference frames without getting hit by either of the doors and no animals are hurt.Assuming the relativity of simultaneity, does this make sense?