We present some corrections of a part of the original paper [5, Sec. 4, lines 14 9-15 9 ]. In addition, we give examples of manifolds related to the presented corrections. Further, we denote by S and κ the Ricci tensor and the scalar curvature of the product manifold (M × N , g = g × g), respectively. It is obvious that rank S = rank S and κ = κ on U C ⊂ M × N. Now [5, Eq. (24)] yields on this set rank S − κ n − 1 − (n − 2)L C g ≤ 2.