In Rocket League, as in life, it's not over until it's over. This epic end of the match clip proves it. So no matter what your best friend or that internet rando do or say, you owe it to yourself to see every match through.
Matches don't end in Rocket League until the first time the ball hits the ground after time's been called. As a result, anyone can keep hope alive by getting under it and chauffeuring down the field toward the opponent's goal. Some players are talented enough to accelerate just enough that the ball stays almost perfectly balanced on the top of their car while others strike well placed, last minute shots.
Maaivy and his teammate managed to do something even harder, tossing the ball back and forth between one another and the walls until a beautiful flick at the end set up the perfect shot. Team blue could have probably defended the attack if they'd kept their heads about them but when the clock hits zero people have a way of coming apart at the seams. That added tension and anxiety is part of what makes it so hard to score after the buzzer's sounded, but despite all of that Maaivy and his teammate managed to keep their final attacking play alive for a nineteen total seconds after it should have originally one dead. I know because I counted.
The Western Regional Finals, in which the above match was played, are still going on and can be watched live here.