Who knows what really happened? If he/she died, how are we to know? Also, how can we differ a normal address from Satoshi's? An address with some early transactions could be a possibility, but the fact remains that he/she could not be alone in mining during those times. He/she could've had his/her friends know about bitcoin back in the days and those people could've mined some coins out of curiosity or help for their friend. There are A LOT of possibilities and probabilities as to what really happened to Satoshi. The only way we can be sure of who he/she is is that someone would stand in the hot seat, prove that he/she is in fact the genius behind bitcoin then problem solved (well it isn't really a problem in the first place).