The culpability is two parts. First part is serving a beverage that was much hotter than what an average consumer would expect, without a warning such as "this

The culpability is two parts. First part is serving a beverage that was much hotter than what an average consumer would expect, without a warning such as "this product will cause third degree burns within 3 seconds of touching your skin". But the biggest issue that I don't see mentioned most times this case is brought up is that the coffee cups at that time were defective by design. They relied on the lid for structural integrity. When you grasped the cup and squeeze it hard enough to keep it from falling, then if the lid pops off the cup collapses and the cup falls, spilling scalding liquid on you. Notice that the current cups don't crush as easily even without a lid on, they still hold their structure when squeezing it hard enough to pick it up. Also, the old cups would cause discomfort when holding them, which indicates that the liquid lost a lot of its thermal energy to the environment in a short amount of time. Due to that, customers that had to transport their coffee for some distance before wanting to drink it would want it to be served hotter than normal. Then it would be the perfect temperature when they get to their classroom / office. The newer cups have much better insulation properties, so this is less necessary.