I’m not 100% sure, but I think I remember that when I was young there were shuls that used Hertz. I think that just might have been the Chumash that shuls used. There probably was nothing else that had an english translation, and maybe people were vaguely aware that it was problematic (I remember being vaguely aware of that even though I was a little kid), but that just was the Chumash that was used in shuls and no one thought too much about it.
I think that in the olden days in the US (meaning up to app. the 1980’s), a lot of things were accepted that aren’t accepted now and no one thought that much about them. The Orthodox world back then was very different than it is now.
So my guess is just that this shul is a very old shul and probably out-of-town, and they are still using old Sefarim. It doesn’t mean they approve of everything in the Chumash- they just might not have thought about it that much or they don’t have money to buy new ones.