Tax attorney on the certified letter Cheeto sent about his taxes

[onenote]

26. No.

First of all, the tax opinion letters I've seen rarely have attachments, so I don't know what the attorney is referring to when he suggests that back up information is "always" provided. Indeed, the typical tax opinion letter contains a disclaimer by the attorneys that they are accepting the factual premises on which the letter is based as true and have not independently verified them.

Second, and more significantly, the attorney-client privilege has next to nothing to do with whether tax returns can be obtained through "discovery" in non-tax litigation. Instead, the courts have created a "common law" privilege specific as to the discoverability of tax returns through subpoenas in civil cases. In most jurisdictions this privilege is "qualified" -- meaning it can be overcome through a showing that the information in the tax return is relevant to the case and cannot be obtained through other means.

In the case of a criminal case, the standard for subpoenas seeking tax returns is presented in 26 U.S.C. § 6103(i). Again, attorney-client privilege has nothing to do with it.

As noted above, the letter sent by Trump's lawyers isn't a "tax opinion letter" -- a very specific type of legal document. It's not clear why the tax attorney quoted in the OP would analyze it as if it was a tax opinion letter.