So it appears that the XDCAM Browser wasn't able to open it.
QTInput does indeed just give green junk.
Amusingly enough, though, FFVideoSource was able to load it (I had checked the list of supported formats and didn't see xdcam and called it a day, at first). I didn't think it would support it. DSS2 and DirectShowSource also worked, so it seems I do have a directshow decoder for this, too.
At that point I just tried opening the mov in mpc-hc and check which filter was doing the decoding under Play > Filter.
MPEG-2 Video Decoder. Which means XDCAM EX is just a fancy name with a fancy fourcc for MPEG-2. Wikipedia seems to confirm.
I should have just checked first. Hell, the mediainfo said it too.
So you know what?
The best solution should be to open DGIndex and drag and drop the mov there. Then use the good ol' MPEG2Source to open the d2v. If that doesn't work, then just use FFVideoSource.