Helper function to catch version errors when trying to update an Array field in a mongoose Model

catchVersionErr.js

// --- Dependancies ---
var _ = require('underscore');
var mongoose = require('mongoose');

// Any function that makes an update to a mongoose model that has an Array field can
// use this to catch version errors, and retry the update at most two times
var catchVersionErr = function () {
  var updateFunc, callback, context, args = _.toArray(arguments);

  context = args.shift();
  if (!(updateFunc = args.shift())) { throw new Error('catchVersionErr: must supply a function to do update'); }
  if (!(callback = args.pop())) { throw new Error('catchVersionErr: must supply a callback'); }

  var _count = 0;

  // Add a wrapped callback to the args Array
  args.push(function () {
    var err = arguments[0];
    if (err instanceof mongoose.Error.VersionError && _count < 2) {
      _count += 1;
      return updateFunc.apply(context, args);
    }
    callback.apply(this, arguments);
  });

  updateFunc.apply(context, args);
};

Example Usage extending Aaron Heckman's example:

Post.findById(postId, function (err, post) {
    // handle errors
    var comment = post.comments.id(commentId);
    comment.body = updatedText;
    catchVersionErr(post, post.save, callback);
});

I'm finding that catchVersionErr catches the err, then retries without error - which seems fine, but my doc isn't updated. Question: when the first attempt fails, is the new __v (version) retrieved and the model updated with that new version? If not, how would this work?