[stouset]

Sorry, I missed your reply to this. In case you do ever read this, my point is that:

    (risk of an amateur hand rolling AES * risk of poor implementation by an amateur) = risk of poor implementation by an amateur + epsilon = 1

Even experts make mistakes in these things, but amateurs don't even stand a chance. An amateur will make more mistakes doing both, for sure, but there are bound to be enough catastrophic flaws that it simply doesn't even matter at that point. More real-world attackers are going to try and exploit your abstractions on top of AES than try to exploit your AES implementation itself.