Eh I misspoke, I don't think you can actually brick anything with this, its just it might not boot properly, you can still format over it, or fix it if you run a LIVE Linux disk to rollback. You also always have an option to run previous system configuration.

The more I think about it, I don't even use Pacman, I just use the other tool that comes with Endeavuor, which is a face to Pacman and probably shields me from doing doofus things. Pacman is easy to screw up an update with.