Method and System for Use of Network Affiliation as Basis to Determine Channel Rendered by Content Presentation Device

A computing system detects a channel multi-match with non-matching programs, based on fingerprint-based ACR analysis of digital fingerprint data representing a channel rendered by a content presentation device. The system then responsively determines a channel rendered by the device through a process including (a) determining that channels of the multi-match group are all affiliate channels of the same network as each other and (b) determining, as the channel, which affiliate channel of that network serves a location of the content presentation device. The system then uses the determined channel as a basis for carrying out of at least one channel-specific operation, such as recording audience-measurement data and/or invoking dynamic content modification.