That's why they call it risk. You can never be certain of any risk or completely eliminate it; you can only mitigate against it. Whether you are expecting something to happen or not is completely irrelevant. The question is what did you do or what could you have done to prevent it? By putting coffee between your legs, you are increasing the risk to, rather than mitigating against, any number of possible outcomes....again, regardless of whether you expect any of those outcomes to actually happen.
Unfortunately, the law is results-oriented.
Let's say someone takes a knife and lunge at you. At this point, he know that a knife is capable of killing you, so you can safely assume that that's his intent. You dodge and punch him in the face, knocking him out. A witness saw the event. He goes to jail and gets charged with assault with a deadly weapon. Probably pleas it down and gets probation.
Now let's take the same situation, except this time he actually stabs you. You go to the hospital and survive. Now it's attempted murder. Now he's going to prison for a few years.
Now let's take the same situation and you die. Now it's murder 2nd, and he's going to prison for 25-life.
Now let's take the same situation and you die. He then cuts up your remains and pisses on your face. Now it's depraved indifference murder and he's eligible for the death penalty.
Each crime has increasingly more penalty based solely on the outcome, even though the intent and actions were exactly the same. The person with the knife is a murderer, regardless of whether or not he succeeded in killing someone.
Should the law work like that? That's open to debate. But the outcome most certainly matters when it comes to criminal and tort law. Like Cate and I said: If someone doesn't expect 2nd degree burns from spilled coffee, then he is going to be more inclined to take the "risk" of putting it between his legs. The expected outcome is typically weighed in a person's mind when making a risk assessment. By expected outcome, I don't mean that the person said "I'm swift enough never to spill this coffee," but that the person probably never thought that coffee would ever be so hot that she could get 2nd degree burns and permanent nerve damage from spilled coffee.