Regardless of "can" or "can't," I wouldn't stand on a modern balcony that had passed inspection at that height, let alone a crumbly unsecured hole that has made no promise to maintain its integrity. Even if there were hypothetically no risk, I see no rail or even, like, a cable.
A strong gust of wind or particularly intrusive thought could easily ruin one or more lives there.
Knowing a construction worker's usual sense of humor, I'd be afraid of one giving the guy sitting next to them a solid slap on the back as a joke. Especially if they had just expressed a fear of heights.