I trust a generated parser more than a hand-written one. Any parsing algorithm that involves the use of split() is almost certain to be weakly thought-out and have ill-defined behavior for unexpected input. A well-written parser will never read past the first unexpected character, or at least token.
If you're using .split() to "parse" untrusted input, and not even validating it against a regex first, that's an epic fail in its own right.