Tom,
When the script fails to trap for errors, I call it a bug. I assume that the assumptions/geometries in the code fail below a certain angle, and this may be by design, but the parameter value should be restricted to prevent this. I am not necessarily faulting the author of the part. It may have been written before values lists were available and error trapping was was a major pain and not always possible. It could also have been sloppiness, lack of testing, or perhaps the thing is just to damn complicated (this is a problem with GDL itself in my opinion).
