One of the theories I'm seeing is that the owner dismantled the item because they didn't want to maintain the AM station, just their FM translator. The alleged theft is just a cover store to cover their actions.

The AM station was fairly small at 1KW, and only had a 200 foot tower which is also rather small. Some folks looking into it found public records from the FCC showing that the owner has be fined or found to be out of compliance for only using the FM translator with the AM station off air in the past, so this points to possible motivation.