One of the dependencies that, when found in the summary but not in the article, indicates a possible error is the "pobj" (object of preposition) dependency.
Furthermore, we only match *pobj* dependencies when the target word is "in", as in this example.
In this case it's obvious that "in U.S." is not found in the article, as "U.S." is a hallucinated entity itself as discussed in the entity matching paragraph.
So technically we don't need dependency comparison to spot the error from this summary.