A simple way of accounting for ungrammatical -ing forms in (22) is to assume that the -ing complement of a perception verb is not a verbal gerund, but a participial VP.
i argue that the structure of the VP of (22b), for example, is like this: The unexpressed subject must be coindexed with the accusative direct object, just as in other object-Equi verbs, also in accordance with the Control Theory, which we will discuss shortly.