There are two side to a coin! So while this side looks benign of any issues, you can't assume the other side isn't worse off!
As we don't even see any signs of liquid in this image is this truly the logic board in question or just a found image to mark up?
Lastly liquids often have other stuff within them besides pure H2O. In truth it's not the H2O you need to worry about its whats within it in solution like acids, salts and sugars! You often need to neutralize these so future damage is abated.