Does notice of assignment preclude equitable set-off?

Counsel for CIBC quotes the following passage at para. 32 of Holt v. Telford as authority for his position that notice of assignment does not preclude equitable set-off: “Thus, cases involving debts that arise from the same contract or closely-inter-related contracts form an exception to the general rule. In these cases a debt arising out of the contract or closely inter-related contracts may be set-off against the assignee even if the debt accrues due after the notice of assignment.” The general rule to which the forgoing forms an exception is set out at para. 31 of Holt v. Telford: a debt which has accrued due before a notice of assignment is received may be set-off against the assignee.