Righteousness ISN'T "passed like a gas" across the courtroom. (what a dull and insipid analogy). We are "found" in Christ!
Is it at all helpful to point out also that having Christ's perfect righteousness imputed to you is not being given the essential righteousness of the judge, or the righteousness of his verdict? It is the obedience of one man, though that man is God, which is given to us: it is in that sense a human righteousness (the satisfaction and obedience that man owed to the law), though it is acceptable to God, and bestowed on us by Him.