No. His plea deal was rejected. That is not the same thing.

Right. Plea deals are "I'll plead guilty and save you the trial in exchange for this sentence."

Depending on the court, plea deals can be a horrible gamble by a defendant. Generally you have to enter your guilty plea first, and then the judge decides if they want to let you have that sweet, sweet sentence the prosecution offered.

I know someone who went to court having been offered a plea deal for probation and got 80 years instead when the judge rejected it and sentenced them.

Yeah, this shocked me when I learned it. The actual "deal" is the defendant agrees to plea guilty in exchange for the prosecution giving a specific recommendation of sentence. (In most cases, there are some exceptions of course)

What's the difference (in practice)?

Boeing isn't pleading guilty on its own - it's also agreed to damages.

I agree that a defendant pleading guilty on their own (and throwing themselves on the mercy of the court) would be hard to reject. That isn't what's happened here - the prosecution has, presumably, agreed to the damages, so this is a plea deal, right?

Without turning this into a criminal procedures lecture, the practical difference surrounds who decides the punishment. When a judge rejects a deal they are asserting control over punishment. But a prosecutor can fight back by dropping charges, or reducing to lesser-but-included charges [insert lecture re elements] which would place a cap on the max punishment the judge could adopt. It is a back-and-forth fight between the prosecutor and the judge about who decides punishment, who represents the wishes of the people.