James Gregory ("Barney Miller") gives an affecting performance as a down at the heel prize fighter who calls upon his old buddy Mark to help with a drunken assault charge. Gregory does something a little different with his voice here that I think adds texture to the role and was maybe meant to distinguish the character from a previous part played in the season one episode "Messenger From Beyond."
This is another in a long line of low-key entries that have more to do with taking an emotional stance on an issue than with catch-the-bad-guy action, meaning no fireworks here, just Mark getting his panties in a twist about the inequities of the criminal justice system. And it turns out actually to be more of a showcase for guest-star Gregory than a spotlight for Mark, though Mr. Sanger does get the girl when he seduces his night school-law class teacher.
I liked the scene between Mark and the Chief after Mark returns from seeing his buddy in jail. The dialogue was well-written, logical, and was effective at conveying Ironpants' affection for his aide in an understated way.