Alexa V. answered 05/16/19
Japanese Language and JLPT Prep from an Experienced Translator
Without seeing the page you're referring to, I would wager your instinct is correct. The character you're referring to essentially removed the 「言った」of the sentence (the long, correct form of the sentence being 「私を殺したあの時と言った」). As you assumed, it's meant to be gathered from context. :)