Bug in Number of Chiral centres calculation

I found a bug in the way that Indigo's Molecule Properties node calculates the number of chiral centres.  The attached workflow should demo this.  It seems to be due to the input being a 3D sdf...the 2D sdf works correctly, but something goes amiss when the input is 3D (perhaps related to the input molecule being a piperidine?)

Alastair