One of the dependencies that, when found in the summary but not in the article, indicates a possible error is the "amod" (adjectival modifier) dependency.
In the image above, you can see the unmatched dependency that is found in the summary but not present in the article. "First" is the entity here, and it's the adjectival modifier of the word "phone".
However, this sentence is not factual, since the article talks about a **new** type of flagship phone, and not at all the **first** flagship phone. This is wrong, and the error was found by filtering on this specific kind of dependency.