If a government agency causes or partially is the cause for a private company to go bankrupt because of an agency decision that breaks the law or is due to malfeasance by a public official, what recourse does the business have against the government agency or the official?
It depends on the circumstances. Despite what we would like to believe, most government agencies are not perfect because they are staffed by government workers who sometimes don't care about their jobs. I have run into this problem many times, and there us no way to win once the agency makes it's decision. Your only alternative then is to sue them, and that is both expensive and time-consuming. And by the time you get a decision from the agency, your business is probably ruined anyway. You can try contacting the person in charge of the agency to see if they can help the situation.