Rage-quitting happens thousands of times a day, all over the world, in every single game. They'll get over it, and after a while (sometimes within a few hours), they'll come back again, or they'll find another game, with the same amount of bugs. Facts.
But that doesn't mean we should make comments like: This guy can not manage his anger.
It is NOT our job to judge. Though I must admit, I do have to laugh when people rage-quit