A retainer agreement would be an agreed upon amount, between the parties, that would cover any and all legal work be done within a certain time frame.  A hypothetical number may be $10,000 to $50,000 a year, and he would NOT be an employee of the OPA.  He would of course, process any number of issues or law suits from 1 to pick a number, it wouldn't matter.  A District Court case can be prepared nowadays in probably 5 minutes; most attorneys that do that type of work will go to the Courthouse with 10-15-20 at a time and file with the clerks.  It's not a big deal.  The attorney, in fact, doesn't even need to file the suit in person; they can be mailed to the Clerk of the District Court.  Of course court fees would not be included in a retainer.   Once the suit has been filed, the papers can be served and of course the attorney would have a court date.  They can request the same court date for 10-15-20 filings and do it in front of a judge in an hour or so.  Done.