How many angles of deflection are there? The buyer pays for the product. This is the only industry where a consumer pays for something and the provider can CYA their way out of it.
What happens when the lender has no need to “worry about” it because FHA insures the loan and they get paid regardless?
FRAUD happens
The facts of the situation are not as self-serving as might appear.
The appraiser is being engaged by the lender. The appraiser is working to the requirements of the lender's appraisal policies. The appraiser is preparing the appraisal for the lender's usage and to enable the lender's decision making. The appraiser is being paid by the lender, regardless of where the lender is getting the money to pay the appraiser.
The consumer has a right to a copy of the report but they don't have a relationship of any kind with the appraiser. They are not the appraiser's client. The appraiser doesn't even have the discretion to provide the consumer with that copy - they must defer that request to the lender because the lender controls the distribution of the report. The appraisal wasn't prepared for the consumer's use, the consumer's off-label usage will sometimes have different and conflicting purposes than the intended usage as stated in the report and the consumer's expectations for the appraisal are neither communicated to the appraiser or assumed by the appraiser.
None of that is to say the appraiser gets a free pass for their errors, particularly if there are indications of significant errors of omission or commission or possible violations of the consumer's rights; but the appraiser's relationship is with the lender. It is within this context that the consumer's status to the appraiser-client relationship is that of a 3rd party.
Now the legal implications and applicability are decided based on the law and per the judicial decisions. Similarly, the underwriting policies at FHA are established at that level and are also subject to the requirements of the law. There might be a case against the appraiser for their errors, but what you really need here is legal advice from a lawyer.
The state appraisal board has no authority by which to collect from the appraiser to make the borrower whole; all they can do is levy a fine or suspension of their license or other disciplinary action. The Appraisal Foundation has no jurisdiction over the appraisers, either; and HUD doesn't have any more leverage on the appraiser than does the originating lender.
The only way the appraiser pays is via getting sued, at which point their errors and omissions insurance may pay out.