Can one sue for bad advice? In the specialized marketplace in which we operate we are all dependant on advice of others, be they accountants, lawyers, plumbers, real estate agents, doctors or Rabbis. What if their advice turns out to be wrong causing one a financial loss? Offering well intentioned advice is a wonderful mitzvah; yet unless one is eminently qualified to do so while also looking out for the best interests of the 'client' it is best to remain quiet. Jewish teachings have long recognized that there is an inherent conflict of interest in the advisory role. The advisor is interested in enriching themselves - financial or otherwise - while the client is interested in getting solid unbiased advice. This in and of itself does not present a moral issue provided the advisor has "fear of G-d" engendering an ethical sensitivity that will ensure that the advisor keeps the clients interests uppermost and tries to eliminate all known biases.
While no one likes to pay for poor service there are times when one must do just that. Jewish law looks at two main criteria in assessing liability; the professional credentials of the advisor and whether services were rendered free of charge. Additionally as a general rule liability is only imposed if the loss is due to an error of competence that should and could have been foreseen by a professional advisor. Errors of judgement or analysis in which there was no clear incompetence would not be actionable. Thus an accountant dispensing tax advice which was against the law would be liable for any penalties incurred. The claims of ignorance are just not credible. However that same accountant who suggests an investment that goes awry would not be liable for losses incurred assuming there was no negligence involved.
Interestingly Jewish law posits that an expert i.e. licensed professional is to be held less accountable than a layperson for any errors caused. While such a professional is liable if he is being paid for his services, services offered on a pro bono basis free one from potential lawsuits. You get what you pay for. However that exact same advice offered by a non licensed professional would incur a legal obligation to compensate for direct financial losses even if it were offered gratis. Only if non- professionals makes it perfectly clear that their advice should not be relied upon can they absolve themselves of payment.