Interestingly enough, the radar track of the day's incident has been removed from flightradar 24
N609AG - Aircraft info and flight history - Flightradar24
At the time, I do recall stepping though the logs, and I do not recall ever seeing a return over 140-150kt. Perhaps the test card for the day intended to complete high speed points, but I think the headline might be a bit misleading as it implies a potential causation.