<human>: Condense the text into a few key points

I just found out via a friend who is more of a hardware person that someone has physically unscrewed the back of my laptop and there are scratches and dings on the interior.  I had him take a look at my machine after I noticed it was running really slowly, and after I reformatted it and reinstalled Win7 (intending to give it to my roommate who has zero clue about computers), it eventually stopped finding a bootable disk. 

I have been the only owner, bought it brand new two years ago and have never, ever removed the backing.  The only person I can think of is a fellow programmer I once got stuck for 9 months on a contract with.  He immediately saw me as competition for the contract and would do whatever he could to sing his own praises, get time alone with the owner of the business before I got in in the morning, and repeatedly mused about how much his hourly rate would increase were I gone.  To be fair, I responded with a bit of bluster of my own until I more or less called him on it one day and voiced how tired I was of it all.  The other thing about this guy was that he had a fairly long history with the police including felonious assault.  Also, as I got to know more about him, I found him likable enough, but I would catch him in repeated exaggerations and outright lies.  

I used to bring my laptop to work.  He used to love sitting at the other desk ripping computers apart that the contract would buy him so he could customize them.  I may have left my laptop in the same room with him while out having lunch.

My question....if it was him that removed the backing from my laptop and left the obvious scratch marks on the mother board and failed to reinstall a few of the screws back there, what would he have been doing?  Why not jut a good old fashioned rootkit or keylogger?
<bot>: My laptop, of which I've been the only owner and never worked on before showed obvious signs of tampering when the backing was removed. I suspect an ex-coworker.