MarkoH01: So my end goal is to test the DVD and if it is in fact bug free ... to provide those files to the devs so that they can see the difference and hopefully fix the bug once and for all.
ReynardFox: Best of luck with the investigations.
Just finished those and I can confirm what I said before:
1) GOG and digital TTG version (latest release): Sybil is missing after psychoanalysis and right before that she is stretching her arms when you leave and then enter her office. (Screnshots Sybil1_GOG_TTG.jpg/Sybil2_GOG_TTG.jpg).
2) Collector's DVD: Sybil is working perfectly fine but the version really ran like crap because of the necessary VM ... ever tried to dive with 10-15fps in a game? ;) (Screenshots Sybil1_DVD.jpg/Sybil2_DVD.jpg).
3) It is simpossible to mix those two and it is impossible to remove the DRM.
So yes, it is definitely an urban legend that the game was fixed on the TTG store only. The bug was introduced later and has never been fixed anywhere (maybe on Steam that I can't say). The DVD version however was created before they updated the game with this bug which is why it still is working. Since according to the dev they used the latest TTG build I can only hope that there existed one build that was even newer than the latest official one (which I tested) because otherwise the remaster will have the Sybil bug in it as well. I've forwarded all this to the devs. Let's hope that they are really trying their best - I did what I could and now it is up to them :)