Could be, most if not all of the pumps I have/used have the long cord (pond pump).
No body has ever emailed me saying the mag pump wont fit so I would have to assume the 1/2" pipe threads are correct on both pond and aquarium pumps. The mag 9 and up have 3/4" fittings, not sure about the very large mag pumps.
I think that both measurements are in some sense correct...the actual threaded output is 1/2" MPT, and if you want to attach 1/2" ID tubing you'll need to get a hose barb that is Barb x 1/2" FPT. On the other hand, 3/4" ID tubing fits perfectly over the little threaded nub output of the pump (definitely use a hoseclamp if you do it this way!). I have my skimmer hooked up this way because I'm running it with a Mag 7 and my skimmer input is 3/4". Hope that helps...