The first inquiries help determine whether malpractice has been committed. Malpractice does not depend on "how nice" the professional was. What matters is what the professional did or failed to do? Would a similar professional in the community have done the same act or omission? Is there an injury, loss or damage as a result of the act or omission? Depending on your response to these (and similar) basic inquiries, there may have been actionable malpractice.
You yourself are rarely in a position to know whether or not there was malpractice, and the professional who performed the service may be unwilling to tell you she or he is at fault. (He may not even know s/he's at fault.) In fact often an attorney has to hire an expert or consultant to help assess whether or not there was malpractice. Unless the facts are very clear, you generally would be asked to pay for the cost of that initial assessment.