I think that you have confused something that you have heard relatable to Kevlar laminated directly to carbon fibre.
When Kevlar and carbon fibre are laminated directly together as two separate but co joined laminates there CAN be a "sheer" problem between the two with delamination possible, (that was one reason why a fabric consisting of Kevlar and carbon fibre interwoven “50/50” was originally conceived to solve this potential problem). When Kevlar is used as a “stand alone” laminate, delamination is only possible through “poor workmanship” and not as a result of any characteristics of the material.