Depends on the toplevel suffix. For instance, .fr (France) domains have a "no taking" period after the expiration date, where nobody can take it from their previous owners. The owner can then take it back, but it won't be re-activated for a couple of weeks, I believe. So the punishment for screwing up is a temporary blackout of your domain name.

.com, .net, .org domains are handled differently, and may be easier to lose permanently.