Did you read the beta TOS? I'm not an iOS developer, but I'll bet you a dollar there's some vague language in there that allows this. Not defending Apple (well, not too much), but I doubt they updated your stuff illegally. Which also answers your other question - if the device had WiFi or any other sort of data access, you probably gave it permission to do updates over the air when accepting the TOS. Or, maybe it was timebombed, as most commercial beta software is.