Mac genius turned on MacBook after spill

Question

Hi everyone,
This afternoon I spilled coffee (with cream & sugar) on my desk and it splashed onto my MacBook Air spacebar, command, option, control keys and trackpad. I immediately tried to wipe it off and then turned my MacBook off. Had an appointment a the Genius Bar about 3 hours later, told them what happened and handed it over. They took it to their back room to have a look and returned and told me that the trackpad was malfunctioning, that the warranty doesnt cover liquid, etc... and then turned the MacBook on to show me. At that point, the trackpad was working, but then the keyboard wasn't working right. I asked him what I should do, and he said my choices are either to send it off for a $755 flat rate fix, or to try and let it dry for a while longer and see what happens. 
After reading these forums all night, I'm confused about why the Apple Genius would turn on my MacBook. From everything I've read, it should've not been turned on for a few more days. I definitely was too afraid to turn it on myself, but when the Apple Genius turned it on, he seemed like he knew what he was doing. Did that do a lot more harm to it? Should I even bother letting it dry for another day, or assume that since it was turned on (at least twice...), that it's a lost cause?

Answer 1

letting it dry out will help next to nothing, the "dry it out and turn it on" method everyone seemingly likes to do never accomplishes anything.
sticky sugary residue is left behind to bridge electrical solder points which causes short outs.  (hence sugar being an electrically conductive nastiness).
turning anything WET on is a bad idea yes.
You said "it splashed onto my MacBook Air spacebar, command, option, control keys and trackpad."
Damage was done. If it was very little liquid, then only your trackpad and keyboard are damaged and it will not make (assuming this by guessing from your statement) it to your important logic board.
thankfully there extremely few parts in a macbook Air.
as long as your monitor, IO board, logic board, and SSD are safe.......
but yes, spills migrate, and damage A leads to B....etc.
check your home owners policy to see if youre covered.
Laptop repairmen that are VERY skilled (worked with some and I was one) get frustrated over fixing spills, because dry residue is invisible.....
they fix things they know are bad, inspect for other, but when it works, they give back the repair.......unfortunately the only way to fix problems like this are fix and test......fix and test.....
people sometimes get laptops back as fixed but it crashes and the repairman is made to look like the dufus, but the fact is short of replacing EVERYTHING in the laptop, the dry residue in cracks and crevices is invisible, and sometime you have to just "wait for it to fail" before you can fix it again.
cant fix what you cant see...... Spills in such cases are ALWAYS creeping nightmares to fix,,.....because they often have to be fixed AGAIN.