Vector3.Reflect does not preserve magnitude of vector

I assume when reflecting a vector about another vector, that the resulting vector should be the same magnitude as the input vector but just a different direction. So I'm baffled at why the result I'm getting to this:

var reflectVec = Vector3.Reflect(Vector3(0, -7.4, 0), Vector3(.1, 1.4, 0));

is that reflectVec = (2.072, 21.608, 0).

Is this a bug in how Reflect is implemented? I would expect the Vector3.magnitude of the answer to be the same as the input vector.

 

The surface vector needs to be normalized to give a valid reflect vector.

 

Oh yeah, that makes sense. Thanks!