Does it matter? After reading the law in question (you see the entire thing online by searching for: "US Code -- Section 600: Promise of employment or other benefit for political activity"), it is clear that any offer of a job "directly or indirectly ... to any person as consideration, favor, or reward for any political activity ... in connection with any general or special election to any political office,or in connection with any primary election" is an illegal act.
Conceivably, the United States Agency for International Development was frantically hunting for someone with Romanoff's unique work and life experiences exactly at the time everyone in Colorado knew he was contemplating a challenge of the largely unknown Bennet. Or, perhaps, Romanoff, once a moderate liberal and now running to the populist left, was exactly the kind of recognized contender that could cause trouble for an untested candidate.
You might be able to ignore Sestak, but another similar plot line makes the story far more plausibility.
None of this is exactly shocking stuff -- I was, actually, slightly surprised to find out that job offers of this variety were illegal. Yet, it is one thing for an administration to "urge" someone to make room for a preferred candidate and quite another for it to use its power to offer (or even discuss) a taxpayer-funded position as a payoff.
Don't take my word for it. Axlerod says it's a breach of law.