Integer s = 1 point disclination textures of the molecular orientation of a pentacosadiynoic acid Langmuir monolayer split into two s = 1/2 defects upon laser heating. We explain this behavior by a competition of the line tension of a pi-wall of the c-director connecting both defects with the continuum orientation elastic energy. While the line tension causes an attraction, the orientation elastic energy mediates a repulsive interaction between the half-integer disclinations. Laser heating of the texture locally induces an anisotropic stress in the orientationally ordered solid phase, forcing the molecular orientation into the monolayer plane and thereby reducing the pi-wall line tension.