The part about there was no widespread police corruption was a necessary point in the story. The plaintiff's lawyer was trying to point out her client was the victim of police corruption and served over two decades in prison before he was found to be innocent. It was the city, the defendant, who fed the press the story about widespread police corruption being false the day before the trial began. It was later proved, in the trial, when the original detective testified the original 911 tape was purposely misplaced so it couldn't be used in the original trial which proved police corruption.
As for the age discrimination, Matlock did use her age as a wedge to get her foot in the door of the law firm. The law was to protect older workers from being fired or forced to retire after a certain age and she used it to get hired. The problem I have with this is it's hard to believe a law firm would bend so easily and hire her because she was threat to sue them for age discrimination. All they had to do was to treat her like any new applicant and if she didn't meet their expectations they wouldn't have hired her. But hey, it's TV and anything can happen.
I don't think either item above is RW bullshit but simply story lines.
Spolier Alert: At the end of the show we discover Matlock isn't who she pretends to be.