That's nothing.
The very first time I took apart an iBook (also to replace the hard drive) and put it back together, I put one of the long hex screws in the middle, instead of the short one.
http://mikerichardson.name/tidbits/zachdeadibook/
Guess what vitally important ribbon lies exactly in the path of that screw hole?
http://mikerichardson.name/tidbits/CloseUp.jpg
To add insult to injury, the damage to the ribbon caused a short which took out the Combo drive!
I always make triple-sure now to put the short hex screw in the middle. :'(