If you take time to look at the detail you will see that they exercised options that were about to expire. In other words, they held on to these options as long as possible (why do you think they would do that?). Then they sold the stock after the exercise. Now they didn't sell all of the stock but enough to cover the purchase cost and taxes on the gain.
If they were exercising options that still had a few years to run then you might have a point but the fact that they held on to these options until the latest possible time leads me to believe that they believe the stock has further to run.
Thanks... but if you look at the newly priced options and ones granted so far this year they are at no cost to directors. Plus your link shows the massive amount of class b shares held by toseeee ....he controls almost 10 million total shares in the company not including other family members who are along for the ride.