Are you willing to pay their legal bills after they are jailed and go on trial for committing a "hate crime" assault?
Considering the ethnic makeup of New York City’s police force, it’s debatable how hard the “perpetrators” would be pursued. And there are various ways of disguising one’s appearance to make identification difficult, if not impossible. It IS a parade after all, and it wouldn’t be inconceivable that some of the participants or obervers would want to celebrate their Irish heritage by coloring their faces and hair green. Or wearing green wigs and leprechaun masks. Or something similar.
And it’s very likely that no one in the crowd would see anything ... anything at all. And from what little they did see, the poor Irishmen were attacked by a gang of tutu-wearing faeries, and did little more than defend themselves.