2. How do Twombly and Iqbal affect the standard for assessing mixed questions of fact and law under Federal Rule 12(b)(6)? HARTFORD ACCIDENT & INDEMNITY CO. v.

MERRILL LYNCH, PIERCE, FENNER &SMITH, INC., 74 F.R.D. 357 (W.D. Okl. 1976), was a suit by an insurer that had issued a blanket banker’s fidelity bond against a brokerage firm for failing to notify a bank that its employee was engaged in margin-stock transactions.

Treating the question of proximate cause as a question of law, the court held that the allegations were insufficient to show a causal connection between the bank’s negligence and the loss on the fidelity bond. If the apposite state rule treated proximate cause as a question of fact, would a federal court sitting in diversity be required to follow that rule when deciding a motion to dismiss?