British or European
Seeing as how this guy is a Texan the voice could have been anything that wasn't Texan or Mexican. People in Texas aren't exactly known for their vast knowledge other cultures. This guy is a rare example in that he was able to seperate Britian from Europe; his wife probably watches Downton Abbey or he couldn't even have made a guess.
Hacking a baby monitor is straight creepy though. I hadn't even considered that people would do that. I should've known better.