The fact that the ungrammatical cases were graded, with pronouns next best after gaps (see Table 3) shows that the network wasn't just using the simple rule "If it starts with Wh*, pick the version with fewer words, if not, don't".
the overwhelming effect of processing factors like the level of embedding (Figure 2), and the fact that the apparent success of the NN in the island task in not based on the island extraction effect itself cast doubts on the idea that the NN is using an abstract dimension of 'grammaticality'.