Considering OP said he did nothing he could think of that might cause the trouble, but we have direct evidence that he was achievement boosting (which is particularly banned because it means you're giving out your personal/account info to strangers), this means at the very least OP was lying, and knowingly lying to try to shift blame elsewhere.
In light of that, we don't have reason to take anything he says at face value. I bet there's more "dirt" in terms of his behavior to be found, whether or not it comes to light. More or less.