$3.2m / 43 = a bit over $74K each.
Seeing that it can give out up to $2K a ticket, and according to the article it returs your second ticket when you use 2, you need to somehow rack up enough to accumultae onto your $2K for one ticket, and then just play with a single low cash ticket in front.
Cashing out in this manner, you "just" need to do it 37 times. As this went on for "weeks" (and they didn't say months), I would guess something like 5-10 weeks. At the lower end with 5 weeks, that's 35 days. Do it once per day and you're good...
Probably a large % went to a small amount of the 43-44, meaning that they probably did more than the average, which would be indicative of it being organised... But even repeating this 5-10 times per day could be done relatively discretely.