Yesterday I was at a wedding, and a vase broke in the aisle shortly before the bridal party was to enter. Guests quickly picked up the pieces, but the vase left a pool of water on the hard floor.
A security guard ran (literally) for a mop and cheerfully picked up the water. He could have easily stood in the corner and said that mopping floors is not his job. And if he were guarding a jewelry store, it would be inappropriate for him to leave his post to get a mop. But his presence at the wedding was a formality, presumably a venue requirement, and no one was endangered by his fetching a mop. There was more danger of someone slipping on a wet floor.
I enjoy seeing anyone do their job with enthusiasm, doing more than the minimum required. Over-zealous people can cause problems, but I’d much rather deal with such problems than deal with people passively putting in their time.