The issue here is "what is incorrect code?" -- a web coder can serve up completely valid code, according to the w3c alidator, that is really awful (this, also, is purely subjective). For actual scripting languages the same is true - a coder can serve up code from procedural hell but it runs perfectly. There may be global variables everywhere, a complete lack of business logic and no input checking on user supplied data but it could still do what it is supposed to do 100% of the time.
That's no different from code in any programming language.
