I’m not too crazy about the confusion of the terms, but when it comes to laws, confusing the terms is downright shameful.
I think the origin of the confusion comes from World War II when the soldiers were issued a number of different firearms with the designation of “M1”. The M1 Garand was loaded with 8-round En-Bloc clips. Meanwhile the M1 Carbine and the M1 Thompson both were loaded with detachable magazines.
Since soldiers were issued ammo in different containers, I can see how the terms could be easily confused. But its 2013 now, people! The only time clips are used is in shooting military surplus guns like the Garand, or the SKS, or when soldiers are given clips of ammo to faster reload their magazines.
A simple rule of thumb, if it has a spring in it, and it actually feeds rounds into the chamber of a gun, its a MAGAZINE, if it is just a piece of metal or other material (like those cardboard and metal chargers for the Swiss K31) that holds the rounds together for easier feeding into the magazine, then its a CLIP.