CatBus said:

I thought crappy old 4:3 letterboxed DVDs would be hard-telecined, but maybe they just have the pulldown flag just like modern DVDs.

Unfortunately for the buying public, hard-letterboxed DVDs aren't an age issue, but are a shoveling-slop-to-the-hogs one.

It's easy to tell native from telecined. Just check any fair amount of movement, like in this comparison of the DVD (24fps) to a broadcast (30fps), again from 2010:

The overlapped-frame fields of 30fps is always distinctive.