FWIW, 95% of carbon fiber parts you see are hand made. This goes for everything from your carbonio intake to boeing dreamliner parts. The layup in these cases is fairly easy (as they're non-structural components for the most part, and you're not dealing with extremely high pressures or vacuums or anything of the sort), although you are dealing with heat. There is the possibility for resin discoloration due to heat and/or chemical exposure, but it would be a gradual issue, not a sudden discoloration unless something was VERY wrong with the resin - and then it would not have been localized like this. What you're likely seeing is thicker resin along the seam of the "flag(s)" cut for the curve - there will be seams top AND bottom, it's not like a welded pipe.
The other 5% (wild guess on %) is formed either through "Pultrusion" (the analog to metal extrusion) or robotic layup, which is basically just automated hand layup but extremely expensive, so it's reserved for specialized components where perfect layup is critical. Think billion dollar war planes. Pultrusion MAY be used for straight sections of tubing, but CANNOT incorporate any bends, so the part in question is not done with this process.
FWIW, I DO work with composites on a day to day basis. I spend most of my time with injection molded polymer, extruded high strength aluminum, machined aluminum, and cast steel (plus a bit of fabric and foam thrown in for fun), so I wouldn't consider myself a composites "expert" but I'm certainly familiar with the material and manufacturing.