Why aren't I seeing dropped frames?

Normally I can see dropped frames easily, such as when importing a 30fps clip into a 23.976 timeline. But I can't see dropped frames in the latest clip dumped into the timeline, but that clip is different – it's 25 fps. I've looked and looked but no dropped frames. I want to understand why. Here is the background. I'll work in frame units not time units.

• I captured a PAL VHS tape into ProRes 422HQ.
• The capture shows up in Premiere's Project window as Progressive, but Premiere is wrong. It's actually interlaced, Upper Field first.
• So I intrepret the clip as Upper Field First and place it in the timeline. Looks beautiful. No interlace artifacts. If I don't interpret, I can see the interlacing. So let's say it's interlaced.
• In the Project window, Premiere reports the 25fps clip as 46640 frames.
• In the 23.976 timeline, Premiere says the clip is 44729 frames. The frame ratio (44729/46640) is exactly the same as the fps ratio (23.976/25). All is good so far. 1911 frames have been dropped.

The problem is – I can't see those dropped frames, and I don't like it when my understanding of what should be happening, differs from what is actually happening.

Ques

What could explain the lack of visible dropped frames? Is Premiere doing some fancy blending of the interlacing?

If anyone would like to play aroung with a 5-second extract from the clip, I can upload it. Maybe you can work out why Premiere reports that clip as Progressive and why the dropped frames are not obvious.