Kidd's torso was hit by Shanks' no-touch CoC zone. In the doublespread, it was shown in the center. After the doublespread, it was even clearer. Kidd was shown spitting blood while his torso disappeared completely, that was Shanks' "slash/swing" whatever hitting his chest-stomach and decorated with black lightning flying around. And Kidd's chest was not cut at all, so Shanks cut gave blunt damage.
Well if you just want to imagine hypothetical scenarios, i can also imagine both Roger and WB depleted all their CoC and only their weapons were left, resulting in Roger scarring WB. Anything can happen in offscreen, it doesnt have to be Roger disrespecting WB's strength...even when Luffy's base / G2 attack was avoided by hybrid Kaidou.