No owner may retaliate against a renter for the renter’s assertion or exercise of rights under this chapter by threatening to bring or bringing an action for possession, causing the renter to quit involuntarily, decreasing any services or increasing the rent. In an action by or against the renter, evidence of the assertion or exercise by the renter of her or his rights under this chapter within three months prior to the alleged act of retaliation shall create a presumption that the owner’s conduct was in retaliation for the renter’s assertion or exercise of rights under this chapter. "Presumption" means that the court must find the existence of the fact presumed, unless and until evidence is introduced which would support a finding of its nonexistence. (Ord. 5109-NS § 11, 1978)