IP would be absolutely trivial to spoof so that's not a proof of anything really.
AFAIK even regular cell sites have GPS for timing purposes.
There are also 911 implications.
https://cdn.ymaws.com/www.nena.org/resource/collection/1F053...
If you move it, and call 911 - how does the carrier determine the address where the call originated?
The technology would have worked just fine, they just couldn't fill in their E911 entry with anything that would work.
There is so little tolerance that people are finding the dish only works say, in their driveway because the dish's required location is based off mapping data that puts a certain address at certain coordinates, regardless of where the house is (which might be set back considerably from the road.)