FF-360 bug

HTML

<script src="https://getfirebug.com/firebug-lite-debug.js"></script>

JavaScript

const alumni = [
	{ Id: 22, Name: 'Harry' },
  { Id: 4, Name: 'Fred' },
  { Id: 9, Name: 'George' },
];

const optOuts = [
	{ Id: 4, OptOut: true },
  { Id: 9, OptOut: true },
];

console.log(_.merge(alumni, optOuts));