Who is right? Assuming that the Frum passenger is wrong for doing what he did:
Should our hero involve himself in what was going on?
Was our Frum passenger correct when he told our hero to mind his own business?
If we are assuming he is wrong he is not correct for not listening to someone telling him so, and it isn’t his own business because it reflects badly on all frum Jews.
Even has their own rights and wrongs though, so this can be complicated. Even if you’re sure you’re right, chances are he feels the same and will not take kindly. I would leave it and let him cook his own can and explain to the guy next to me that he is a חסיד שוטה.