In this day and age, it is important to maintain a sense of humor, even in the government. That being the case, rather than issue a presidential or state pardon to remove someone from their conviction, I implore you to instead, present them with a letter, and a (perhaps gold, or relatively fancy) legitimate "Get Out of Jail Free" card. It would be practically the same, the only difference being the name, and the fact that is an actual card. Also, I don't believe you would have to worry about any form of copyright infringement, since the term "Get Out of Jail Free" has practically become genericized from major use in popular culture.
Besides, at the end of the day, who wouldn't want a legitimate "Get Out of Jail Free" card hanging up on their wall?