So I dug into this a bit, and I found out part of the problem was a unit conversion error, which was easy to fix. In 1.2 we'll be increasing the range at which ship kills generate unrest at a port from roughly 40 miles to roughly 100 miles.
This will create a few situations where you can generate unrest at a port outside of the PvP area of that port. This is not ideal, and something we would like to change in the future, but we think the impact should be minimal. If there are two ports within 100 miles, only the closest port gets unrest, so the total number of places where unrest can be generated outside the PvP radius around a port is very small.
While we're not pleased that unrest can be generated outside the PvP range of a port, we do not consider doing so an exploit.