When you start breaking rods down into technique specific rods then the differences can be seen. In this case the two specific rods in question are very similar in what you need them to do. So like Catt and others sometimes use the same rod. If you compare what makes a specific "Pitching rod" vs what makes a specific "Jig rod" there really is not a big difference.
Pitchin rods - Generally these rods are fairly long, roughly 7' 6" in length and have a heavy action with little parabolic bend. You want the tip to have a little give to it, for pitching accuracy. The lure rating generally fall somewhere into 1/4 to 1 1/2 oz. range. Its not uncommon for these rods to be referred to as a "broom stick".
Jig rods - Generally are a very sensitive rod with a fast tip. The rod needs to have a lot of power to pull out big fish, while having enough of a tip to pitch or roll cast the jig accurately. These rods are lighter and will have some parabolic bend to them generally not as much as a pitchin rod. Todays standard is generally more closer to the 7' range, heavy action, with a fast tip but some prefer longer. The lure rating generally fall somewhere into 1/4 to 1 oz. range.
So you can see these rods are pretty similar. They overlap in many areas. The length of a pitchin rod is generally slightly longer, has less parabolic bend, and the lure weight is slightly heavier in most cases. So considering all the different anglers personal preference in feel, along with the variances in rods from brand to brand along with what anglers perceive to be the "right" way to do things its not unheard of for someone to see them as the same rod. All of this does not take into account how nasty of stuff your Pitchin into or your jig size. If you're fishing a really nasty slop where its not uncommon to pull out as much grass as the fish weighs and you're doing it with a 1 oz or more bait, looking for bigger fish, hooking 5+ lb mommas it will become more evident how less effective the Jig rod is. And you can say the same for the reverse. It would suck really bad casting a true Pitchin rod with a 1/4 oz jig all day.