Hey Chris,
You should be fine, Google understand that some people will accidentally click an ad, if it is not a reoccurring thing they will ignore it.
However I don't think Google would have your IP blocked as with most internet connections you have a dynamic ip address. This means that every time you connect to the internet or refresh your connection (if it is always on) you are given a new IP. So if Google blocked it then someone else who gets assigned that IP address later would be blocked.
I would probably say that they checked their cookie on your computer and tracked that your computer has been logged into that AdSense account. Something along those lines.
Thats just my thoughts anyway, I know you didn't really need to know everything I said but hope you enjoy it in some way.