The classic case of this type was the one brought against McDonald's 30 years ago. It has been represented as a frivolous lawsuit in popular media since. The fact is, however, that the plaintiff suffered third-degree burns and permanent disfigurement from spilling 88°C coffee on herself. It's easy to say people should know coffee is hot (and I think the warnings printed on coffee cups since are rather obvious and silly), but food really shouldn't put you in the hospital.
This is a similar case: the plaintiff suffered permanent injury. According to the article, the lid on the cup wasn't secure, so it would appear that the Starbucks bears greater responsibility for his injury than McDonald's did in their case - that woman's scalds were, at least, self-inflicted from carelessly taking her own lid off.
She was awarded about $3M, reduced to around $640,000. I would agree that a $50M judgment is excessive.