This paper proposes CSVC, a novel framework for causally informed video editing. While existing research on applying the text-to-image (T2I) latent diffusion model (LDM) to video editing has demonstrated excellent visual fidelity and controllability, it struggles to maintain causal relationships in the video data generation process. CSVC formulates counterfactual video generation as an externally distributed (OOD) prediction problem, considering causal relationships. It encodes relationships specified in the causal graph into text prompts to incorporate prior causal knowledge and guides the generation process by optimizing the prompts using a visual-language model (VLM)-based text loss. This ensures that the LDM's latent space captures counterfactual variations, leading to the generation of causally meaningful alternatives. CSVC is independent of the underlying video editing system and operates without any internal mechanisms or fine-tuning. Experimental results demonstrate that CSVC generates causally faithful counterfactual video results within the LDM distribution through prompt-based causal adjustment, achieving state-of-the-art causality without compromising temporal consistency or visual quality. Because it is compatible with any dashcam video editing system, it has significant potential for creating realistic 'what if' video scenarios in a variety of fields, such as digital media and healthcare.