“As you point out, the plaintiff should have obtained letters rogatory (letter of request) instead, or and alternative service at one of the many TD branches in Miami.”

Right, except service at a branch in Miami wouldn’t have been “alternative service.” It’s simply the ordinary way you serve a big national (or international) bank. If I want records from Bank of America, I send a subpoena to its main office in Boston; I don’t bother with a commission and subpoena in North Carolina!

Parenthetically, under the Ontario Rules of Civil Procedure, service of a subpoena (summons to witness) on either an Ontario resident or by inter-provincial subpoena, must be made personally and not by an alternative to personal service, such as regular mail, international registered mail, email or fax.