This one's easy. Insert spaces between every blip and you've got a sequence of E and T. This should demonstrate to the proctor that the problem is ill-posed. Now the proctor is under examination: if they admit that the problem is garbage, they pass and you should stick out the interview. Otherwise, just walk away.
A sibling comment discussed most probable message; on further reflection, I suspect there's a dynamic programming algorithm for the shortest possible message... this problem could have some nifty angles to explore if done right. But only if you know that you're testing on how people work in the face of ambiguity!
