router.put Set by Index not ObjectID

This is my first pull request my apologies if I'm doing something incorrect. I think there was an issue in  

router.put(reGet, function (req, res, next) {

When the code was running for a subdocument that was an array of sub documents.  It was trying to set 

  tobj.set(last, body); However last was an object ID and the Mongoose code would bomb out