At one point in October Sky, the "rocket boys" launch a rocket that lands at the mine. Homer's dad gives him quite a talking-to, and everyone is gathered around listening. His dad calls him a thief, referring to part of the rocket's being made on company time in the welding shop. When Homer talks to his mom at home later, he mentions that he was upset. According to our material on defensiveness (which turns out to be exactly what he says, too!), why would Homer have been so upset?