Uh, how would you have an erie question on that essay? It was in a state court...
Uh, you can have an erie analysis on any question of any exam, no matter what the subject. Sure, you may not get any credit for such an analysis... but I like to think that the professors appreciate the extent to which I will go to remind them of the wonders of classic phrases such as "purposefully availed" or "stream of commerce."
Ex. On my legal ethics exam yesterday, I made sure to incorporate an erie analysis. The fact pattern was essentially this: Man, a criminal defendant, threatens to choke the prosecutor to death the next day in court and tells this to his lawyer; what ethical obligations does the public defender have?
I began my analysis with the following exchange: Professor xxxxxx, the only obligation of any kind that you need to worry about is your obligation to give me an A. That said, the Lake Erie case clearly controls here... (Followed by a brilliant discussion).