[textbook]Traversing the Ethical Minefield Problems, Law, and Professional Responsibility by Susan R. Martyn (z-lib.org)(1) (1)

conflicts are always consentable.
When lawyers work in firms, the conflicts of each lawyer are imputed to the firm.
Lawyers who move between firms carry with them conflicts arising from matters on which
they worked or about which they have knowledge. Former or a prospective clients can give
informed consent to imputation and consent can be conditioned on a screen or firewall
designed to prevent the tainted lawyer(s) from having any involvement in the subsequent
matter. In some prospective and former client situations, these screens may be used without
client consent.
A. Former Client Conflicts Model Rule 1.9 RLGL § 132
Western Sugar Coop. v. Archer-Daniels-Midland Co.
98 F.Supp.3d 1074 (C.D. Cal. 2015)
Consuelo B. MARSHALL, District Judge. . . .
The underlying case arises from false advertising claims relating to the marketing of
high-fructose corn syrup (“HFCS”), pitting the sugar industry [plaintiffs] against the cornrefining
industry [defendants]. . . . Defendants [include] Ingredion Inc., (“Ingredion”). . . .
Plaintiffs, represented by the legacy law firm of Squire Sanders & Dempsey, LLP
(“Squire Sanders”), filed the instant lawsuit on April 22, 2011, [asserting] one cause of
action for false advertising under the Lanham Act, alleging that Defendants misled
consumers by use of the term “corn sugar.” . . .
On June 1, 2014, the law firms of Patton Boggs LLP (“Patton Boggs”) and Squire
Sanders combined to form Squire Patton Boggs (“SPB”). SPB remains the Sugar Plaintiffs’
counsel of record. Ingredion . . . [moved] to disqualify SPB from representing the Sugar
Plaintiffs in this action because SPB is now adverse to . . . Ingredion — a long-standing
client . . . of the legacy firm Patton Boggs. . . .
. . . Ingredion first retained Patton Boggs in May 2004, and Patton Boggs continued to
perform work for Ingredion over the years and last performed work for Ingredion [about
two years ago]. Patton Boggs has provided legal services to Ingredion on at least fifty-six
different occasions, and since 2004, Ingredion has paid Patton Boggs over $230,000 in
legal fees.
Shortly after [another defendant’s] counsel raised the conflict, SPB sent Ingredion’s
counsel a letter . . . advising it of the merger and that Squire Sanders had been representing
the Sugar Plaintiffs and SPB would continue to do so going forward. The letter stated that
if Ingredion wanted to have its lawyers from Patton Boggs do any new work, it would be
necessary to obtain a waiver from Ingredion due to the conflict presented by SPB’s role in
the present case. . . .
Ingredion . . . move[s] to disqualify SPB from representing the Sugar Plaintiffs in this
action. . . .
. . . If an attorney undertakes to represent a client adverse to a former client without
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