Yes but gags are funny because they're just humor and isolated, don't affect the overall story.
The bloody nose had him nearly die and them have to find a donor that opened up the main plot direction. It didn't stay isolated and waved off. It affected the story to make them have to split up, have arguments, learn things, and save him. If he didn't have one, they wouldn't have learned of the law, met certain characters, or had to make choices. That's when it stopped just being a gag.
So to make my brain accept that writing direction, I gave it medical explanation to explain how it was possible in the first place to be a big enough threat to affect plot.