Considering the DoJ is expecting to use these documents for their own case against Google, I don't see how they can argue that it was improper for the employees to get lawyers involved.
If you forward such an email to the attorney and ask something like "thoughts? what are the risks here?" that ensuing email chain is privileged. If emails are CC'd to a lawyer to evade discovery and the other side finds out, that's a big problem, even bigger problem if the other side is the feds.
Generally speaking, judges don't like it when you try to hack the law.
If I go to a lawyer and ask them a question in person, seeking legal advice, even if they don't response and just show me the door, is what I am saying protected? I would think yes.
If I ensure my lawyer is in every single discussion I ever have with anyone else, just to say all my discussions are protected, what would happen? I assume that wouldn't work and there is already a standard on how to handle this for in person meetings.
Shouldn't that same standard be applied to discussions happening through email?