The following sets of people objects have the same relationship each other:
In <PERSON> and his inverted gun <==> forward <PERSON>
In Oslo Forward Protagonist and forward metal lockpick <==> Inverted Protagonist
Therefore what should happen is that whatever state you are in, everything inverted from your perspective should appear to move backwards. That's why when Inverted Sator inverse shoots forward <PERSON>, she appears to heal (from his perspective) because she's inverted relative to him. By the same relationship, when the Forward Protagonist forward stabs his inverted counterpart, he should appear to heal the wound just like the forward <PERSON> appears to instantly heal to the inverted <PERSON>.
Instead, the reversed protagonist appears to have a wound on his own body which is moving backwards from his perspective meaning it appears to move in the normal forward direction to his forward counterpart. What would actually be consistent is the reversed protagonist enters the hallway fight without a wound, gets stabbed with a weapon inverted to him (just like <PERSON> is shot with a gun inverted to her) and then starts to bleed while exiting the turnstile now in the forward direction. Then the original forward protagonist would see the wound move both backwards (on his inverted self) and forwards on the copy of him exiting the turnstile on the other side.
Unless there is some other wound mechanic at play I think the stab wound in Oslo is simply inconsistent with the logic of the movie prior to that point. 516
One cannot argue that injuries caused by inverted objects cause inverted wounds, because then inverting <PERSON> would instantly heal her after the duration of time leading to when she was shot. <PERSON> is inverted not to reverse time and instantly heal her wound but rather for some other explanation of the inverse radiation being less severe and allowing her to heal normally if she is inverted. This is never fully explained and characters' own bodies will always still move forward in time from their own perspective. Things can only appear inverted if they actually are inverted relative to you. I believe the best explanation for this plot point is that <PERSON> wanted to trigger the curiosity of a character seeing something move in reverse and notice it themselves vs seeing it on another inverted person that is farther away. It is hard to even notice that <PERSON> heals <PERSON> by shooting her while moving backwards but it would have been nice if he made those scenes more clear. 516