From what little I've read, it looks like there WERE increased safety measures put into place in an attempt to prevent such an incident from happening again, but in this case, it looks like those measures weren't followed. That of course led to this tragedy. I can't imagine what Alec Baldwin is thinking right now. Like... he just shot and killed someone. But... it wasn't really his fault because he thought it wasn't loaded. So it's probably a mixture of him going "Damn, if only I had noticed or not done whatever" and "Who the Hell put a loaded gun on the table and why wasn't it checked before giving it to me?"
Edit: Oh, looks like other people commented about the increased safety measures. Hah. Guess I should have read further before responding!