forum 7: week of 27 Feb - pragmatic encroachment

(3) if "option O will have the best outcome of all your available acts, then you are justified in doing O." It seems if it is a matter of doing something completely affecting yourself, seen in the Bank example, where staying in line would be the best option if stakes were high. If, on another example, say where your sister fell and broke her leg after falling through a crack in the middle of a frozen lake, the best option would be to bring her back before she freezes, taking the risk of walking across the lake (knowing there was a chance it would crack again). Even though stakes were high in this example, it seems the best decision would be to rescue her, whereas if it were a matter of walking across the lake individually, the best option would be to stay put. Perhaps I am missing the nature of the stakes, or the best option (or this may even be a question of ethics). Perhaps (3) is justified when only the individual is under consideration.