A legal professional can be personally liable for not checking the most recent case-law.

The knowledge cut off gap means they don't know about the most recent case-law.

I've seent his happen multiple times now. Professionals drafting letters and missing recent case-law which handles their exact case. It's unreliable.So it can save you some work; but it can't save you all of the work. And in some cases its mistakes really force you to redo all the work, and more, to be thorough and have confidence in the result.