Mongo updating a user

Question

I have a sample piece of Node.js code which pulls a user from the database based on an email, does some checks, does a findOne by ID and updates, like this:

 User.findOne({ email }, (err, user) => {
if (err) { return next(err); }

if (!user) {
  return res.status(422).send({ error: { message: "User doesnt exists", resend: false } });
}

if (user.auth.used) {
  return res.status(422).send({ error: { message: "link already used", resend: false } });
}

if (new Date() > user.auth.expires) {
  return res.status(422).send({ error: { message: "link already expired", resend: true } });
}

if (token !== user.auth.token) {
  return res.status(422).send({ error: { message: "something has gone wrong, please sign up again", resend: false } });
}

User.findByIdAndUpdate(user.id, { role: 1, auth: { used: true } }, (err) => {
  if (err) { return next(err); }

  const { email, firstname, lastname } = user;

  res.json({ token: tokenForUser(user), email, firstname, lastname });
});

});

Could I not just update and save the user I already have, like this?:

Token.findOne({ token: req.body.token }, function (err, token)
{
    if (!token || token !== user.auth.token) return res.status(422).send({ error: { message: "Link doesn't exist or has expired", resend: true } });

    // If we found a token, find a matching user
    User.findOne({ _id: token._userId }, function (err, user)
    {
        if (!user) return res.status(422).send({ error: { message: "We couldn't find a user for this token", resend: false } });
        if (user.isVerified) return res.status(422).send({ error: { message: "link already used", resend: true } });

        // Verify and save the user
        user.isVerified = true;
        user.save(function (err)
        {
            if (err) { return res.status(500).send({ msg: err.message }); }
            res.json({ token: tokenForUser(user), req.user.email, req.user.firstName, req.user.lastName, req.user.company })
        });
    });
});