Same here, except it was the chimpanzees I'd seen go out for food and come back.
In all my years of zoogoing, with multiple visits to three institutions, I have only seen apes outside last month and that brief instance with the chimpanzees. Lincoln Park's Great Ape complex is massive and has well-designed outdoor habitats for all three apes, but they have usually been indoors.
It's part of why I never thought as deeply about Brookfield's gorillas living indoors-only until recently; even though Milwaukee and Lincoln Park offer them outdoor access and I have always agreed completely the animals deserve choice, my mind is so used to gorillas being indoors where they had a choice that it was hard to fully appreciate how unnatural it is.