The 400 foot limit is imposed ONLY for class 'G' airspace. All other classes the limit is whatever the club/individual and local ATC agree on.

Now, can anyone tell me what class airspace the event was in?

In addition, for such an event the sponsoring club could have obtained permission from the FAA to fly higher. Anyone know if that was the case or not?

Didn't think so. You guys just flunked your FAA test for recreational drone flight.

So basically we have people who may or may not fully understand the rules. On BOTH sides of the border. We also may have some who state only enough to raise a fuss from others. There's a name for that.