As part of enabling DXF output of 3D objects via OpenJSCAD.org, this bug was found. Obviously, the 3D objects are ill formed but the polygonToTriangles() function had a bug.
I'm happy to say that almost all examples can be converted to DXF now. The exception is the Globe example, which will take some time to analyize due to special functions.
z3dev
commented
6 years ago 
As part of enabling DXF output of 3D objects via OpenJSCAD.org, this bug was found. Obviously, the 3D objects are ill formed but the polygonToTriangles() function had a bug.
I'm happy to say that almost all examples can be converted to DXF now. The exception is the Globe example, which will take some time to analyize due to special functions.