Not the same logic at all.
Being given the wrong medicine is entirely different due to the relationship between patient and doctor. That is a relationship defined by the position of trust the doctor has. It is a privileged relationship. And a Doctor is known to have years of training and experience behind his belt.
The relationship between a customer and a minimum-wage worker employee is entirely different. You don't expect them to have the years of training and experience behind them to help ensure everything runs smoothly.
You step into someone's hot tub and the water was (actually) boiling. Now you have second degree burns from the waist down. But you should have known better. It's called a hot tub, right? You knew there was a risk that you would be burned by the water. You're just an idiot for assuming that you could just jump in. Stop waisting the court's time. Zero dollars.
(There is no 'position of trust' with a 'hot tub operator,' nor do you require years of training to own/operate a hot tub).
The relationship between a customer and a minimum-wage worker employee is entirely different. You don't expect them to have the years of training and experience behind them to help ensure everything runs smoothly.