A third party could have rooted it. This seem highly unlikely. In fact, I've never heard of it. And, add to that the serious hurdles I had to go through to r

A third party could have rooted it. This seem highly unlikely. In fact, I've never heard of it. And, add to that the serious hurdles I had to go through to root all the phones I ever rooted (3). Your statements amount, to me, to overblown risk.