Then it was pretty foolish of you to just say "I can't." with no elaboration when the waiter asked about telling by taste. Well, either foolish or a deliberate bait so you could berate him more easily. Neither option looks good.
If you wouldn't have answered like that, then the story isn't about you.
It's a joke, and not a serious dialog, exactly because there may be a difference (not necessarily life and death, but maybe the price), but it fades beside the fact that the drink is so bad that its taste is incomprehensible.
If you wouldn't have answered like that, then the story isn't about you.