That's the way I usually do it as well, though using return instead of halt is a preferable way to stop a script's execution. The other example is a nicer way that lets the user who flooded know that he/she was ignored. It all depends what you want to have happen. With the ignore, that user can't use any commands for the bot during that time period and it affects just that one person. With the other method, no one can use this one command during the time perdiod and the nick who flooded would still be able to use other commands. The downside that I see with ignoring one nick as a method of flood prevention is that a lot of clones can still flood you off with that one command.
