BRepFeat_SplitShape returns invalid result

For the appended case BRepFeat_SplitShape returns an invalid result.
The problem can be fixed by fixshape command.

Output of checkshape for the result of BRepFeat_SplitShape:
Draw[163]> checkshape r
 **** probleme de SameParameter au point :
         138.440245989498 4.80797485827721 94.119065519402
   Erreur detectee :9.33966118487734e-006 Tolerance :5e-006
 **** probleme de SameParameter au point :
         138.440245989498 4.80797485827721 94.119065519402
   Erreur detectee :9.33966118487734e-006 Tolerance :5e-006
On Shape faulty_1 :
BRepCheck_UnorientableShape
Shape faulty_2 on shape faulty_1 :
BRepCheck_InvalidCurveOnSurface
BRepCheck_InvalidSameParameterFlag
On Shape faulty_3 :
BRepCheck_UnorientableShape
Shape faulty_2 on shape faulty_3 :
BRepCheck_InvalidCurveOnSurface
BRepCheck_InvalidSameParameterFlag