Polselli v. IRS: Can the IRS seize the financial records of your lawyer to investigate you?

Remo Polselli owes for $2 million in taxes and penalties to the IRS. The IRS is searching for Mr. Polselli’s assets and demanded the financial records from the banks used by the law firm he was a client at. Does this seem like unconstitutional overreach to you? The IRS did not even notify the law firm that they were doing this. Usually the IRS would need to notify people so that person could then sue the government to prevent the summons. Congress passed legislation that basically says the IRS does not need to send any notice if they are trying to collect against a person.
What Mr. Polselli is arguing, and I would agree with, is that the IRS does not need to notify Mr. Polselli that they are trying to get his bank records, but the IRS can’t be secretive and seize the records of his wife, his lawyers, or other people associated with Mr. Polselli. If you have no idea the government wants to seize your bank records and other financial information, how can you go to court to argue that it isn’t unconstitutional?
In the last couple of years we have seen unprecedented agency overreach into all aspects of our lives. The law is supposed to come from Congress, not from alphabet agencies. Do you argue with me and Mr. Polselli? Let me know in the comments.