You're basically closing down the patent system here, any prior disclosure anywhere in the World, in any language can be used to show the invention lacks novelty.

There are some restrictions in different jurisdictions on what can be used to show there is no invention (ie there is no 'inventive step' or it's 'obvious' [it's a legal definition, not just a dictionary definition of this term that is used]).

If you're going to hold an examiner liable (there's actually a law in the UK protecting civil servants from liability, but hey) then you're going to have to give them lots of time and lots of resources ... that's going to make it all too costly.

You'll spend more than is profited from most patents in order to be sure that a patent won't be challenged in court ... and it still could be, just under other facets of the law, such as whether the disclosure is sufficient to work the invention.

You have to allow people to be less than perfect. If you're a programmer, imagine you had essentially unlimited liability if you created a single bug (examiners don't know if the patent is worth nothing, or 100s-of-$Millions, that's all down to externalities).

Could the system be improved, for sure, but it's always going to have to balanced against cost of administration. If you're court system is working effectively you don't need anything like a perfect parent examining system. If you're courts aren't working ... well fix them instead of spending disproportionately elsewhere.