Don't worry too much about it
I worked as a composites tech for a number of years. I laid up a lot of c/f panels by hand and actually braided carbon fiber unitape into structures. I never got to do the really cool 3D carbon fiber braiding though. What i did get was a lot of nasty splinters.
I don't know how that insert was processed but I have seen that a number of times. Sometimes that happens. Happened to me enough even with hand lay-up. Sometimes things shift in the mold, or the bag/tooling draws down unevenly.
Here's the good news: if it were a carbon fiber
sticker, it would be perfect, so you really have a carbon fiber part.