Yep, as stated, this could just be o-ring wear due to the tight fit, which the RSF bolt is known for.
It would be odd for the slots to be cut after anodising, as this would then suggest that no de-burring/polishing were carried out after the slots were cut. Definitely something you might want to mention to Critical.
Do the slots actually feel rough to the touch? If they do, then I wouldn'y suggest fixing this yourself. You may just make matters worse. Talk to Critical.