GeomAPI_Interpolate -> Load - wrong behavior if only 2 points - tangentFlags are 'ignored'

Load (const TColgp_Array1OfVec &Tangents, const Handle< TColStd_HArray1OfBoolean > &TangentFlags, const Standard_Boolean Scale=Standard_True)

TangentFlags are ignored under the following conditions:

2 Points (x,y,z)
P1 (0,0,0)
P2 (0,10,0)

2 Directions (x,y,z) (as sizeof(points)==sizeof(tangents))
dir1 (1,0,1)
dir2 (0,0,1)

Array for TangentFlags:
[1] false
[2] true

GeomAPI_Interpolate spline ...
Load(tangents, tangentFlags, false);
perform();

=> dir1 is also evaluated
the resulting spline is not planar as would be expected

if there are 3 ore more points Load(...) works as expected