Oh, and just in case
that we eventually
might see a sample here ...
It is this description
When I play it on VLC, if I choose BOB deinterlacing the motion looks interlaced but really weird, kind of like those new TV sets with that 120 Hz frame blending abomination.
that makes me suspect that it's in fact a fieldblended NTSC -> PAL conversion. If it was a clean 25p or 25i source, then bobbing should not show up any abnormalities.
And IF so, there's two cases: progressive origin, or double-fieldrate/'true video' origin. The former usually can be cleaned/backconverted with Srestore. The latter is virtually impossible to be repaired.)
That's the good interpretation.
The bad interpretation:
With a kosher source, motion cannot look "interlaced" after bob
deinterlacing (unless the bobber used unreasonable thresholds). However, there is the possibility that at some point an improper vertical scaling was performed on interlaced frames, wich in turn destroyed the correct field structure. In this case, you often see something that looks like "broad interlacing" after bobbing.
This case usually cannot be repaired either.
There's a dozen of different possibilities what the source actually could be like. No point in basing decisions on "let's assume it is 25i". You can't pick and choose the scenario. The scenario is given & fixed, and the processing must fit the scenario. Not the other way round.