Systems and methods are described for identifying a content source of media content being transmitted to a viewer in situations when a specific media asset is being transmitted to the viewer from two different content sources nearly simultaneously. For example, if a certain movie is being broadcast at nearly the same time by two different channels, the system is able to identify the channel that the viewer is watching. The system performs the identification by obtaining content identifiers for two different channels, matching the content identifier based on time and then finding a divergent pair of content identifiers by iterating in reverse chronological order through the pairs and comparing the content identifiers. The system then compares the content identifiers to content identifiers in a log that stores content identifiers and timestamps for content that the viewer is consuming. The matching content identifier corresponds to the correct content source.