A subway car full of New Yorkers watched in stunned disbelief as the four Scandinavian cops, all in civvies and unarmed, leapt into action. They used non-lethal techniques to pin the two combatants without hurting either one and then began trying to talk them down, calmly, never raising their voices, and avoiding any swearing or verbal abuse. Neither man was hit by any of the officers despite their struggling. As the Swedish cops waited for New York's Finest to arrive, they gently rubbed and patted the distressed captives and spoke to them reassuringly.
It was not the way that situation would likely have gone down had it been four off-duty New York cops in that car. First of all, they would almost certainly have had guns on them. Second, they would have been shouting and upping the tension level. Third, they might well have applied chokeholds instead of arm restraints, and would have had the men pinned face down, with knees in their backs. Quite possibly punches would have been thrown along with kicks and stomping in a gang-banging frenzy. Given the history of prior such incidents, it's conceivable that shots might even have been fired, and that passengers could have been hit by stray police bullets (as happened in a Times Square incident not long ago). One or both of the fighters might well have been injured or even killed.