I have to agree with the professor on this one. Posessions can be replaced, but data, nay, MEMORIES, are much harder to.
I'd probably feel the same way if my PS3 was stolen, and the next week, the hard drive or something was returned. I'd say, "Damn, well, that's 300 bucks down the drain, but at least I've still got my game saves".
The PS3 is just hardware, but the data is all of the battles I've had, the challenges I've overcome, and the stories I've experienced. THAT'S what's really important.
Stealing is wrong, but I feel the thief, perhaps, may have been stealing for something other than greed. Perhaps he needed food, or he had bills to pay. This is all speculation, of course, but it IS nice to believe that there's still goodness in the world.