I got this strange glitch where I barely missed the goal but the game counted it as me crossing the goal. The confetti effect didn't even play. Maybe we can use this to save fractions of a second on other levels.

This is known within the community colloquially as a goal-post rip. They can be used to shave frames off of certain IL (Individual Level) strategies, but recreating them in full-game runs is inconsistent to say the least. You can see a bunch of really gnarly goal-post rips like the one you posted here in various TAS runs, like this one:

is it rare?

Not particularly, no. But they do come in all shapes and sizes, and the one you posted is pretty aggressive!