Once again you are reading from the manual, instead of observing actual behaviors. Of course most Jews even Orthodox will enter a church. Funerals and Weddings happen all the time. My friends were Akiva Cohen type Orthodox. Wear the beanie, only eat Kosher, etc. The main rule with regard to churches was that they could not participate in what was going on. Respectfully observing was fine. Most of the Pastors, Priests and Rabbi’s in my town were members of a local “interfaith council”. Which was a clever way of saying they all had a long running Tuesday Night poker game. Life happens. Community happens. People are different than rules.No one's reading into anything, though. Just stating facts that he's not THAT religious if he lets his kids participate in Halloween. Even Modern Orthodox, who are assimilated with secular culture, don't do that. The co-workers in your story don't sound like Orthodox Jews, either. Orthodox Jews get excited to share shift work with non-Jews because it means they can cover the secular/Christian holidays for them while the non-Jews can cover the Jewish holidays for them. Going into church sanctuaries or mosques is verboten if you're following Jewish law as the Orthodox do. Akiva Cohen-type "Orthodox" would probably do it anyway.
In Cohen’s area the only groups that do maintain such rigid standards to said rules are the Ultra Orthodox Jews, mainly the Hasidim, (whom the other Jews as a rule hate.) and the more deeply Evangelical Christian groups. (Whom the other Christians are largely embarrassed by).