In all of the other episodes, Dexter has a neighbor on both sides of his house. However, in this episode he does not.
Dexter takes off the clear globe he was wearing as a helmet, but when he turns to face the general, he is still wearing the globe. A moment later, when he is squirted, the globe is gone.
Computer: Good morning, Dexter. My radar is picking up faint readings of an incoming, unidentified fighting force.
Dexter: Who? Who is it?
Computer: (sarcastically) Umm, hello! Unidentified, as in I don't know!