What happens when your mechanism for checksumming doesn't work? What happens when your mechanism for installing after the checksum is validated doesn't work? I

What happens when your mechanism for checksumming doesn't work? What happens when your mechanism for installing after the checksum is validated doesn't work? It's just too early to tell what happened here. The likelihood is that it _was_ negligence. But we need a proper post-mortem to be able to determine one way or another.