Yeah, really good question and a pretty important one. Keep this in mind:
The past perfect tense is never* required. (I'll put that * there because I teach Critical Reasoning for a living and get nervous saying "never" but man I can't think of an occasion where you cannot use simple past and instead must use past perfect.)
Past perfect exists to put additional emphasis on the fact that one even happened prior to another. But using simple past isn't wrong in those situations. Consider:
Past Perfect: Before he even considered getting an MBA, John had already earned graduate degrees in law and public policy.
Simple Past: Before earning his MBA, John earned graduate degrees in law and public policy.
In the past perfect, "even considered," "already," and "had" all serve to put extra emphasis on the fact that John was a total academic badass even before thinking about getting an MBA. Past perfect here is about signaling how much he accomplished pre-MBA. In the simple past, it's more a factual list of John's accomplishments. The past perfect version is probably what you'd expect a speaker introducing him for a presentation to give (let's really showcase how impressive his background is) while the simple past might be what you'd find in a more sterile biography on a consulting company's website.
Note: it's the same sequence of events with one clearly happening before the other, but both simple and past perfect can work.
So for the more general question of "hey shouldn't this be past perfect?" just keep in mind that there's no sequence of events for which simple past is dead wrong and past perfect is required.