Regarding "SQL is not typed": as a matter of fact you can always type-check your queries against a transaction. If it fails, there's your syntax and type error right there. If it doesn't fail, then it either reads, or also modifies the database. But when you are in a transaction, you can simply not commit the transaction. You're always isolated. You can always check your SQL, safely.

BTW the author doesn't know what the word "liability" means.

As for Post-ORM, like ORM it treats the DB as a hidden implementation detail, which means no free interaction with existing DBs and uneasy solutions when something isn't in your abstraction, but it's trivial in the database itself. This approach has its place, but it doesn't seem like Post-ORM as much as a continuation of what ORM did in the first place, including many of the problems following.