The person swearing was in a car, the recipient was jaywalking. I heard a sound like the jaywalker might have touched the driver's car in some inappropriate way but I wasn't looking until the swearing.
@dr2chase by which I assume you mean "pedestrians ought to just be able to cross if they deem it safe"? Which I would generally agree with but posit that most people in greater Boston do a terrible job of (the deeming safe part)