Sounds to me like fluid went through the keyboard and trickled down the cmos battery wires where a droplet shorted out the battery at the mobo.
It's great that your laptop has recovered, but what makes me nervous for you is that bleach does not fare too well with copper, zinc, tin, etc, and even your silver based mobo map has these ingrediants in it's alloy. Most certainly the solder does, and those points are most likely to come into contact with the caustic chemical.
Microcrystals may grow like a fuzz on them and eventually com into contact with one another shorting circuitry, and even though the resistance may be high, it's still like adding a resistor where it doesn't belong.
I do not have an easy answer as to how to remedy this. I myself would rip the whole thing apart and thoroughly clean every bit with cotton swabs and distilled water. But even then, it would be a long time before I would trust it 100% after that enough not to back up everything you care about on that hard drive.
I'm not sure, but securing your internet connection and enable file sharing will keep you fairly safe from preditors but allow you to be able to access your data on that hdd if you ever need to remove it and read it on another computer via enclosure.