DV capture exported by iMovie and mpegstreamclip reported as different file "types"?

[Cox Orange]

I noticed this issue some time ago, tried to investigate, then after I was stuck at some point, I left it be. Now I did another start on it.

This time I found someone, who could do some analysing of some limited sort.

First what is the case?
I once captured PAL S-VHS with iMovie. As we all know, iMovie (up to vers. 6 at least) saves the stream as .DV in a project folder (acessable via "ctrl+click -> show package content -> media", or just navigating in Finder for Version 3 and lower).
Now, if you choose export/send -> save as "highest quality" it will create a .DV file. If you open the files in the project folder with mpegstreamclip and then export, again a .DV file will be saved. (unless you choose export/send -> as Quicktime movie and then choose some codec).

Now, if you open the resulting files in mediainfo, you get:
a) from iMovie (I name it "capture" from now on) = reported as DVCpro
b) from mpegstreamclip (name it "pass-through") = reported as DV
x) if you open the file that iMovie wrote into the projectfolder, with mpegstreamclip, it is reported as DV.

There question was, is there a difference in the resulting file?

(from what the person who analysed it for me said)
The "capture" (DV) and "pass-through" ('DVCPro') samples are bit identical. What's more, both have 4:2:0 chroma subsampling, which is interesting, as by definition DVCPro(25) is 4:1:1. (Talking about PAL DV).

So why MediaInfo reports the export file as being "DVCPro" (Commercial Name), I'm really not sure.

Regardless, I think it's safe [is it?] to conclude that it is a direct stream copy of the source DV. DV is not a lossless format, and if there was re-encoding going-on, you would expect to pick up some loss in quality on metric analysis. And there is none.

Speculating
Maybe the "name" change by iMovie is due to poorly or better say sloppy conduction of the PAL standard, after the application (iMovie) had been written with NTSC parameters/flags/tagges etc., when they then tried to change it for PAL, there went something wrong maybe? Like the DV, that iMovie saved IS DV-PAL, but for some reason when exported it is "renamed" to DVCpro(25) and mpegstreamclip just reads soemthing like a tag or flag? - Just purely speculating!
If you open the file that iMovie wrote into the project-folder with mpegstreamclip, it is reported as DV by mpegstreamclip, which is why I say it gets somehow misnamed upon export (misnamed, but not converted).

Anyone having an idea? or actual knowledge, because he worked in the video scene or at Apple back then?