Perhaps they also performed an RF Safety Evaluation and found that they were exposing your neighbor to less than the MPE limits. Your neighbor, on the other hand, is being exposed to the sum of the energy from your station on one side plus the energy from the cell tower on the other side. Let's start to examine your neighbor's house in this age of the wireless gadget. Perhaps there is a wireless baby monitor. Your neighbor may have a wireless alarm system, where all of the sensors are connected to the controller with RF links.
Wireless telephones are common in homes.
Your neighbor can also use a cell phone from the house. With most of these RF sources, if you do the math you find that even adding up all the exposures you stay well below the MPE limits. Let's think about the future, however. I'll leave the horrific RFI implications of this for my friend and ARRL Lab Supervisor Ed Hare, W1RFI, to consider. The FCC deals with the multiple transmitter issue from the point of view of a transmitting site.