Brown spots/yellow tips after accidentally breaking a blade

one leaf showing differently to the rest should cause no concern. From what I can see the rest of the plant is super healthy. I would pull that leaf off and see if it happens elsewhere. Often fan leaves may develop a spot or two and die after a while. They are nothing to worry about though when a fan leaf dies and falls off as this happens all the time. What you will also notice is that in area where the plant is growing to densely the fan leaves also die off. Training and thining the plant out often feels wrong but can help produce a much healthier plant. Happy growing pal