IMO, if you think your account can get banned from any activity that was happening on it, I'd suggest you hold your adsense payment and remove the Adsense ads from your site for a few weeks. maybe for a month or two. Put your adsense ads back on your site after a month and make sure you dont do any thing wrong again. Hopefully, your account wont get banned.
I dont think this should lead to a ban. Since the traffic and users were all unique, and your site was also getting an increased number of users, it shouldnt be a problem. I'm considering the fact that most of the users coming to your site were coming from search engines directly, and were not forcefully driven to your site, like in a traffic exchange network or something like that.
Forget Adsense, if i go to pee leaving my PC unlocked, i'll get fired, its voliation of information security. I think whenever there are fraud clicks or unexpected rise in earning, google moniters everything and then decides. Accidential clicks happens most of the time, wats important is ur whole click profile, there would have been something fishy in ur clicks profile which brought the immediate blocking.
That there is the difference between me and you. I once accidently clicked an ad on my own site as I was testing links, I emailed them straight away. Why? Because an Adwords Advertiser is paying money for a legitimate visitor to click on their ad. It's serious business. And honesty should be the only policy.
Google Analytics can be useful in these kind of situations.. If you have had it installed, you could have just passed your login to Google and assuming you didn't click on your ads, Google would be able to see all the stats from there and hopefully won't ban you...