From the Washington Post website, a headline:
U.S. weighed spy swap well before 'sleeper' agents were arrested
I wouldn't call this a crash blossom -- its ambiguity is too discreet for "crash," and either reading of it makes sense. Still, I parsed it wrong (I think) before I parsed it right. Did the US weigh the spy swap "well" -- thoroughly -- before making the arrests? No, I think the WaPo means that the US weighed the swap "well before" the arrests.
Since this sort of thing is both work and play for me, I don't mind having to think twice. But headline writers are supposed to make it easy for readers; so why the vagueness (and syntactical ambiguity) of "well before"?
Well, on the jump we learn that the administration began considering a swap "as early as June 11" -- two weeks and two days before the arrests. So "weeks before" would have been technically accurate, but (having just made it into plural territory) would read as overstatement. "Well before" avoids that pitfall because (like the incredibly elastic journalistic "recently") it's a flexible term. To me, in the context of spies you've been watching for years, "well before" suggests months, perhaps years; but there's no rule that says "well before" can't mean "a couple of weeks before." And so it does, in this case. I think.