The errors (demonstrated)

/*
Example:
var val = createInstances([0,1,2,4,...<set of ascending integers>]);

Instructions, each time user stalls, give the new "bug report"

1. val.total is giving me NaN!
   * If a candidate sees the typo (but not that total isn't set), point out that the bug is still there.
   * If the user sees the reason it's NaN, then ask whether the other properties are being set correctly
2. It's not always adding listeners to the right items
   * This is caused by the fact that it is using ItemFinder.find(i) instead of find(list[i])
3. It always says that position is some bizarre number instead of the current index!
4. I'm getting a weird null object error!
*/
function createInstances(list){
  // 'use strict'; recommendation would mean that the below would all
  //      be safer.
	var item,
      notifier = og.notifications.getNotifier(), created, updated, total 
  // The fact that there is no comma at the end means that 
  //     results looks up the parent scope (no good)
  results = {};
  
  // This calculates list.length every time the for loop is run
  // `<=` instead of < means you could have an out of bounds issue
  // Bonus for using $.each or [].forEach instead.
  for(var i =0; i <= list.length; i++){
     // total is declared (good), but it isn't set to a number!
     // Not technically a bug, but incrementing total seems a bit
     //    ridiculous when you can just set total = list.length
     total++;
     
    // ItemFinder.find should probably be for list[i]
    //    (this is code which should not "look right")
    item = ItemFinder.find(i);
    // typeof null is 'object', this should probably be !item instead
    // Technically not needed, but points for recommending (typeof item == 'object')
    //    or  typeof item != 'object'
    if(!typeof item == 'object') {
    	item =  new Item({created: new Date(), 
               updated: new Date()});
      created++;
    }
    else if(item.needsUpdate()) {
      // updated isn't incremented here.
      item.updated(new Date());
    }
    else {
      // Another uninitialized value.
      unchanged++;
    }
    // Could this cause an item to be listened to more than once? (not a guaranteed bug, but
    //    bonus points for noticing.)
    item.watch('update', function(evt){notifier.transmit({event:evt,item:this,
        // i is bound to local scope, which means that at the end of the loop it will always
        //     equal the last value, not the position in the loop.
        position:i});});
    item.save();
  }
  // not all of these values are initialized, and not all of them are updated
  return {new:created, updated:updated, old:unchanged, 
      // this is *clearly* a typo.
      total:totla};
}