Steve Deever, the jailed man who never appears in Arthur Miller's All My Sons, is shown to be only partially responsible for shipping the defective parts that cost the lives of American fliers during the war. Although Deever still shared in the responsibility for the crime there were circumstances that slightly mitigated his guilt. The first is his position in the firm, the second is the way he was manipulated by Joe Keller. Keller makes it clear that Deever was completely under his control in business matters. He even says that he once "had to fire a mechanic to save his face" (414). Deever was clearly dependent on Keller and subject to his authority. This is a point his son makes about him when he describes his character as that of "a frightened mouse who'd never buy a shirt without somebody along" (406). In his position Deever could go along with what Keller told him to do or become a whistle blower; his whole life was in Keller's hands. But Keller also understood Deever's character perfectly and used this knowledge to manipulate him. He knew that Deever's fear of the pressure from the army would, in combination with Keller's own pressure, force him to choose the unethical course of action. It may, therefore, be a flaw in Deever's character that made it easy to use him this way, but this does not excuse actions that showed careless disregard for people's lives.
Joe Keller decided that he had to protect his business and, he claims, his family by allowing the parts to go out and, as an essential part of his self-protection, allowing the blame to fall completely on Deever. When Keller tries to offer a little justification for his actions he says that he assumed he could gain time by shipping the cracked cylinder heads and that someone would stop them and send them back before any damage was done. But he was, ultimately, willing to risk a few deaths in order to save his business. In this he resembles Peter Stockmann, th...