The ham sandwich can be invoked as a defense for someone who feels wrongfully accused. This comes from the saying that a good prosecutor could indict a ham sandwich, thereby pointing out that one should not presume the indicted is guilty.
Tom Delay, a congressional majority leader in the United States, was indicted on ethics violations. His colleagues came to his defense by invoking the "ham sandwich" defense. This defense became well known when Delay defender Senator Mike Rodgers confused the public by misusing the phrase when he said "... any attorney knows you can get an indictment with a ham sandwich." Obviously he meant "against a ham sandwich."