Technically true
Stretching the truth isn’t unheard of when it comes to letting agents and landlords. You’re probably used to seeing particular language in apartment listings. For example, “cozy” means small, and “friendly neighborhood” means that there are frequent all-night parties.
Technically, when the landlord, in this case, told his prospective tenants that there was a pool, he wasn’t lying. There is a pool, it’s just that the pool is closed permanently, so it’s of no use to anyone. I would be pretty mad if this is what had led me to choose this particular apartment.