Stop on failure not working with illegal option errors

[Chemaclass]

Q	A
OS	macOS / Linux / Windows
Shell	bash 3.2
bashunit version	0.18.0

Current behavior

I was working on another feature in another project and I found this.

• When an illegal option error is found and the -S (--stop-on-failure) is enabled, the running does not stop

Expected

1. Stop the runner when that error is found.
2. Investigate if -S is not working for other errors or only for this one.