i just tried to remake the bug and i did it again so i have more precisions : the foes wont move but the wolverine will begin a attack animation then stun , they still act like ennemy when alive as they dmg you when you cross them, but not when they'r dead ( and the sprite that stay is a "sliced" sprite (like they'r cut in half)). If i go back to the cave and come again the foes will act normally again.
And i run into another bug trying to remake this one : if you go on left wall while fighting the spider boss and she charge you and you roll through her, she'll be stuck into run animation into that wall and you can kill her freely.