You're absolutely right. You've pointed out more clearly, however, something that I'd already noticed when reading the root node: that the response did not, indeed, actually indicate any possible introduction of bugs. These are problems, but not opportunities for more bugs to be introduced. Rather, they come across as characteristics of a bug. That's not to say that hand-rolled option parsing isn't prone to introducing bugs: it is, as indicated by Fletch. This just means that no indications that it is prone to bugs were clarified in the OP's reply.

In other words, hand-rolled option parsing such as is described here is itself a bug. It introduces its own problems at runtime. It should be fixed as a bug. Luckily, it's a bug with a known, relatively easy solution.

On the other hand, I think that the OP's "positive" approach was more diplomatic than the "negative" approach taken in your rephrasing, andyford. What you posted is excellent for illustration purposes in answering the original question, but is not how I'd address the questions of a coworker (if I was thinking properly at the time) because it might be perceived as accusatory.