Prominent U.S. legal cases have turned on the resolution of linguistic ambiguities that arise from interactions between negation and coordination. Negative disjunction sentences (ND, “John didn’t buy cake or cookies”) are ambiguous between two readings: a neither-nor reading and a not-both reading. Negative conjunction (NC, “John didn’t buy cake and cookies”) is similarly ambiguous. Experimental findings on such scope ambiguities (Jasbi et al. 2023, Tobia et al. 2023) suggest that in general, listeners favor the neither-nor reading for ND but are less biased in their interpretations of NC. We present a corpus analysis with researcher annotations of several hundred tokens of these constructions in English treebank data. Initial results are consistent with previous conclusions based on controlled experimental data, suggesting that an attested tendency in linguistic comprehension is also reflected in naturalistic production. Our dataset can further be used to explore factors that modulate the disambiguation in context.