I drew the same shape on all of these points, so why does FreeCAD not extrude them all the same?
@chux0r there are some geometry inspection functions, yes. What seems to have happened here is that FreeCAD decided that 3/4 rectangles I drew with the rectangle tool (as well as the circle I drew afterward) were non-continuous. I have no idea why, or how. Somehow the circle also didn't count as a closed shape. Why it then decided to try and extrude a couple of vectors with a null value in one dimension escapes me!
FreeCAD is absolutely amazing and utterly useless in the same breath...