After dipping my toe into the crypto currency world, learning about the DAO and Ethereum, there are a few things that bother me about this whole situation.
1.) Rolling back (voiding) transactions, which seems to go against the concept of cryptocurrencies in general.
2.) The conflict of interest between the DAO, slock it, and core Ethereum developers, and their hefty co-mingled investments in the DAO.
3.) The labeling of this person as a "thief" when they played by the rules set forth by the DAO contracts. Maybe not the spirit, but courts generally decide that. The code is the law and is final is my understanding. (I don't know how you code the spirit, by the way.)
4.) The non-inclusive "democratic" vote of the Ethereum community on the hard fork that appears questionable.
5.) The different rules for reversing a "theft" depending on whose funds where taken (see #1 and #2) or how much was involved.
6.) The centralized decision making on the fork by a small number of people who stand to lose substantial funds based on a poorly understood investment vehicle.
This whole situation occurred because of some poorly implement code and now there's a whole lot more code being deployed in a hurried manner. If there is another unnoticed, unintentional way to run code that is not within the spirit of a contract in the future and no core Ethereum or slock it funds are involved, will another hard fork occur? Will they legally be forced to do it? It seems as though the risk was contained to the DAO's funds and now, with the hastily rolled out fork, the whole Ethereum market is put at risk.