During a Rocket League rumble match, a frozen ball began falling without any car touching it, and without unfreezing. I know from personal experience that nearby demolitions and plungers can unfreeze balls, but there were no plungers or demolitions at the time.
An earlier answer suggested that it was because the ball hit the wall while it was in its freezing animation, but from my own testing, it looks like the ball still freezes properly in that situation:
What could have caused this frozen ball to drop while still being frozen?
Best Answer
Your test does not properly recreate the situation shown in the example video.
When you freeze a ball, it takes a moment to stop based on its current speed. You can amusingly steal goals from teammates this way.
In your first video while coming to a stop the ball touches the wall, ending it being frozen and thus falling down towards the goal.
In your second video, the freeze is triggered as the ball hits the wall, resulting in the slowing and freezing to occur after the wall strike itself. In the second angle you can see it bounce as it comes in contact with the wall during the freezing process.
As an aside: this is why if not properly timed you can freeze a ball as someone hits it and essentially nothing happens... the time to freeze needs to be taken into account.
Source: I am champ 3 in Rumble.