No joke. All the things we mentioned in the headline really do make appearances in the latest addition to the ever-growing subway-fight-video canon. Here's what appears to have happened: A woman in blue ("Blue Shirt") and a woman in white ("White Shirt") get into an argument over some perceived personal slight while sitting next to each other on the L train. At the next stop, Blue Shirt stands and appears to spray pepper spray at White Shirt while yelling what, if there's any justice in the world, will someday become a sitcom catchphrase: "Real fuckin' rude, bitch!"
Apparently this particular can of pepper spray was strong enough to infuriate White Shirt but not quite strong enough to incapacitate her, because a prolonged and intense fight quickly commences. It is at this time that Blue Shirt's stroller, which happens to contain her baby, literally rolls off of the train and onto the platform. That's just good parenting right there, making sure the baby is at least a few feet away from the pepper spray that you unleashed into the air and the fistfight that you started.