Some readings explain wa-aṣukku by supplying the sense wa-anā aṣukku. The imperfect is still expressed, but an unspoken nominal subject is posited. The resulting circumstantial construction is treated as a nominal sentence containing a verbal predicate, rather than as a direct case of wāw introducing an affirmative imperfect verbal ḥāl.
This analysis is contextual, not a license to invent omitted subjects whenever convenient. The distinction between the overt wording and the full proposed construction must be maintained so the relevant rule is applied to the correct syntactic structure.