Legal writing brings in a lot of context. In this case the disproportionate is meant to denote situations where the action itself isn't adverse, e.g., giving someone money, but that its not applied evenly. Whereas adverse is an intended negative consequence. Its trying to say both are problematic. Although, I understand your interpretation -- its just not what's meant in this case. Unfortunately even arguably our most important legal document, the Constitution, isn't nearly as clear as it could be.