I wondered if that would come back an bite me
After a bit of digging, this iPhone hack is not what is seems. It is basically a code injection exploit and requires the user to install an app. The security issue was that Apple allowed the app into the App Store without noticing the app's ability to receive and execute code that could possibly take control of your phone. The main stream news articles seem to be suggesting that it is possible to just send an SMS in the standard way, which is not the case.
Likewise, the reporting of this issue. This code injection isn't physically possible with ACARS and certainly is not the method talked about in that presentation anyway. That bloke is suggesting that you can generate false alerts, steer the aircraft and even turn it into a lawn dart with ACARS as it is, unmodified and using off the shelf gear. It isn't clear exactly how he demonstrated the vulnerabilities. Whatever, suggesting that he can remotely control the aircraft with ACARS or ADS-B is just looney tunes.