The latest episode of 'Supernatural' was chock-full of Zonks, and thankfully, every one of them can be splained away.....
In separate meetings with their public defender, both of the Winchesters referred to him as "Matlock". The lawyer noted that it was obvious that they were brothers.
There was no indication from the lawyer that he recognized the name as a TV show reference. Nor did Sam and Dean drag out a splainin for the nickname. So we don't have to look upon this as a reality-busting Zonk, where one TV show refers to another TV show which should be sharing the same universe.
For all we know, in some adventure yet unrecorded, Sam and Dean Winchester were investigating some kind of supernatural hoogedy-boogedy down in Atlanta, Georgia. And that's where they met Ben Matlock, a trial lawyer.
And they didn't even have to go to Atlanta to either meet him or even to have heard of his reputation as a defense attorney. 'Matlock' has fought for clients in Hollywood, California, as well as in England. He may act like the down-home cornpone type, but he's got name recognition that's global.
So when they both called their lawyer "Matlock", Sam and Dean knew that he would obviously know the source of the name as well. He might have even worked with Ben Matlock in the past!
In another instance, Dean referred to Pete, the lead investigator on the case, as "Ponch". ("I'm not joking, Ponch.") For the audience at home, this is an obvious allusion to the 1970s TV series 'CHiPs', which starred Larry Wilcox and Erik Estrada. (Estrada played Ponch.)
As has been the case so far with this episode, there was no mention of the TV show. And whether or not Pete understood the reference really didn't seem to matter to Dean. He probably chose it because Pete had a vague resemblance to what Officer Poncharelli looked like. (And Dean would know this because he most likely had a run-in with the motorcycle patrolman while on that same case in which the Winchesters worked with Jim Rockford. (See the earlier blog post about that.)
It could be that Dean didn't know anything about Ponch either. To him, it could have been just a funny-sounding name guaranteed to piss Pete off. He could have called him a Cheech, a Chooch..... Punchy, since Pete was getting a bit physical during the interrogation. But he settled on Ponch. Maybe he had it in mind to play with that nickname; ultimately getting to the variation "Paunch". That way, he could make fun of the midriff the cop was developing.
But that's just a theory. Still, it's a case of reasonable doubt (Look at me, going all 'Matlock' here!), and we can easily toss out any need to splain away the mention of 'Ponch'.