It looks to me like they were coming in hot and the pilot wanted to put the plane down. Rather than holding the nose up and letting the airspeed bleed off he pushed the stick forward to get the plane down once the back wheels were down.
The front landing gear bounced up and the aoa of the wings created the lift to raise the nose up higher. The pilot pushed the stick forward and the oscilliation got worse.
You can do this in a small plane like a 172 if you push the stick forward instead of flareing. Some planes like the Cessna Cardinal are more prone to do it than others.
It was only the brakes and reverse thurst that slowed the jet down quick enough to stop the front gear from collapsing under the load.
I was talking to a 747 pilot on Saturday and he said they have the spoilers armed so that when the wheels touch down they deploy automatically, that and reverse thrust and eventually brakes can stop the jet in very shot time despite the weight.
