No, because the rule only applies if you are “representing a client.” You’re not representing a client in the matter other than possibly representing the person seeking the second opinion.

Not the case. If you are pro se, you have a client: yourself.

It applies to “any person, whether or not a party to a formal proceeding, who is represented by counsel concerning the matter in question.” ER 4.2, comment [3]. So, it applies to representation in any legal matter, regardless of whether it involves litigation.

No, because you then would have impermissibly communicated with that represented person. ER 4.2 “is intended to protect represented parties from undue influence and pressure from an opposing counsel. Even the receipt of a copy of a demand letter, notice of a deposition, or motion for sanctions could unreasonably intimidate an opposing party to make decisions without adequate advice from their attorney.” [State Bar of Arizona Ethics Op. 02-02 (March 2002)]

Parties may communicate directly with each other. Effective 1/1/26, ER 4.2 comment [1] says that “a lawyer is not prohibited from advising a client concerning a communication that the client is legally entitled to make, but a lawyer may not make a communication prohibited by this Rule through the acts of another, see Rule 8.4(a).” ER 8.4(a) prohibits violating the Rules of Professional Conduct “through the acts of another.” Therefore, “advising” the client cannot cross over the line into otherwise violating the Ethical Rules. We do not have Arizona guidance on what constitutes permissible “advising” under the new language in comment [1].

That person’s counsel must give permission for you to communicate with their client. It doesn’t matter that the client contacts you and supposedly opens the door. You must immediately terminate the communication once you realize that the caller is a represented person. You should also advise that person’s lawyer about the contact.

ER 1.0(f) defines “knows” as meaning “actual knowledge of the fact in question.” But knowledge “may be inferred from circumstances,” so you can’t close your eyes to facts that are in front of you.

No. The Arizona Supreme Court rejected a proposed ethics opinion that would have allowed this. In its order rejecting that proposed ethics opinion, the Court said, “ER 4.2 prohibits a lawyer from communicating about the subject of the representation with a party the lawyer knows to be represented and that prohibition does not distinguish between how the communication is made. If a lawyer copies a client on an email, it does not mean a lawyer implicitly consents to the other lawyer communicating with the client.” Be aware that other jurisdictions take the position that copying one’s own client on electronic communication to opposing counsel gives implied consent to a “reply all” response. See, e.g., ABA Formal Op. 503 (Nov. 2, 2022).

See the above answer. But why even raise the possibility that opposing counsel would do this? Don’t copy your client on emails to opposing counsel.

Not necessarily true. ER 4.2 comment [2] says that a lawyer for one party may not communicate with three categories of agents or employees of a represented organization: “persons having a managerial responsibility on behalf of the organization;” “any other person whose act or omission in connection with that matter may be imputed to the organization for purposes of civil or criminal liability;” and “any other person … whose statement may constitute an admission on the part of the organization.” If the current employees don’t fit into these categories, ER 4.2 would not prevent you from interviewing them. If the current employees are represented by the company’s lawyer or have their own lawyers who refuse to consent, however, then ER 4.2 would prevent you from interviewing them.

Not necessarily true. Opposing counsel may contact a represented organization’s former employee unless the former employee’s acts or omissions gave rise to the underlying litigation or the former employee has a continuing relationship with the former employer in connection with the litigation. Lang v. Superior Court, 170 Ariz. 602 (App. 1992). If the former employees are represented by the company’s lawyer or have their own lawyers who refuse to consent, however, then ER 4.2 would prevent you from interviewing them.