Pecon, Greek, myself, and others have all combed this service over thoroughly.
I'm pretty sure all of us looked explicitly for shell injection (which you didn't even mention) shell creation, usage limits, and all manner of other problems.
Why are you posting that on the public forum topic anyway? It's not irresponsible since anyone who wanted to attack would've been smart enough to come up with those attacks on their own, but it's borderline.
If you want to audit this thing, stop asking silly questions in the topic like "omigawsh pecan did you do this" and instead just pm him directly. Maybe he'll let you look it over. I dunno.