I guess that's where backing up comes in. If you've got things backed up to CD or an external hard drive then they're safe if there's a crash. It's the user's responsibility to back up their files.
Unfortunately the LW site doesn't have old versions for download.

That's just the way it goes I'm afraid.
Maybe there should be some extra info on the LW site, making it clear that anyone who buys Pro is responsible for the safety of the installers that they download.