Can’t say but there’s not a lot to verify. About all anyone can do is verify the number IF they had recieved texts from that number in the past. Or verify it came from a phone registered to his office. Even if they called the number, anyone could claim it’s his office. I’m just throwing stuff out there and there could be a million reasons no one has seen him. Not running out for tin foil just yet.
You’re right, there really isn’t much to verify. I was thinking along the lines of something like his wife calling Breitbart and saying “yep, that’s him”. B^)