1. Create a spline object created in the scene
2. Enter in spline context and select a knot
3. Make sure the tangent mode is set to linear in the spline inspector
4. Deselect/Reselect the knot
5. Change the knot tangent type to mirrored

Result
Tangent In/Out properties from the inspector are grayed out as if it was still considering the type to still be Linear.

Expected
Tangent In/Out are available right on selection;