Here’s why I ask:
Roy Glenn is credited as a Bootblack, but does not appear onscreen. With the exception of one quick outside scene the whole episode takes place in an office, so I don’t see where this character would have fit in, so was wondering if the script might have offered some insight.
The simplest answer would be that there was a scene with him that got cut, and they just missed updating the credits to reflect that.
Hmmm. . . Thanks for that insight. I don’t think I ever would have thought about that possibility.
Doesn’t answer the question, anyway, but thanks for the bump, anyway. 
How did you watch this episode?
Let me note some things. Roy Glenn was Black. Not surprisingly, being a bootblack is one of the few parts he could get in movies or television. About half of the parts he got during his life were uncredited. The television show Screen Directors Playhouse was filmed, not live. (Incidentally, it appears to me that the title didn’t have an apostrophe.) Perhaps there was a scene in the show where a white character briefly talks with Glenn’s character. Perhaps some television stations in the South cut that scene down to just the brief outside scene you saw because they didn’t want two people of different races acting even slightly friendly. Perhaps this is why some sources say that Glenn was in the show and some say he wasn’t.
I’ve seen plenty of scenes set inside this or that building — be it a courthouse or city hall or whatever — where a guy works an indoors shoeshine stand; could that have been it?
TCM has been airing episodes of “Screen Directors Playhouse,” which is how I saw this one.
And, yes, very possibly a bootblack scene might have been outside the courthouse. I can see the protagonist wanting to present a good appearance down to his shoes, but it’s not there, hence the question for script info for possible insight.