You can definitely feel that Karlach doesn't typically heal/assist in treating injuries during battle. Especially, when she is trying to help heal you from being immobilized. It almost feels like it is something Karlach is doing because she cares about your well-being, but is half ready to laugh at her poor attempts to assist you.
I was just thinking that xD it's like when my mate falls arse over tit like my first thought is "oh shit are you okay" and as soon as they confirm they are, the laughing at them starts.
I'm kind of curious now. But I would guess if you pick to play as her in the beginning of the game, she would likely still have the same lines. Also sneaking Karlach feels like contradiction 😂
Probably due to the fact that Karlach's VA was hired to portray an origin character and full fledged companion later in production. Mind you, she has voice lines worth a considerable amount of hours. It's just that this specific "hidden" content in the video is kind of lacking for her, I agree. It's a shame, really.