“Final” rejections are poorly named. All they really indicate is that you will probably have to submit a request for continued examination—-and pay a hefty fee—-to continue. Ironically, a lengthy and contentious application process can make the patent more difficult to challenge later, in a more sophisticated setting, because the presumption that the patent is valid is the strongest with prior art that the examiner “considered.” (IAALBNYL)

(Shrug) They had the option to do the right thing and maintain their final rejection. So why didn't they?

It's hard to escape the conclusion that they just couldn't be bothered.

Agreed. The fact they were allowed to resumbit such a broad patent with obvious prior art is ridiculous.

They amended the claims which required the examiner to do another search.

As mentioned above, Final Rejection just means you have to pay more money to continue the patent prosecution. This is called a Request for Continued Examination. RCEs are common.

Generally, the initial filing fees provide for two rounds of examination -- a non-final rejection and then a final rejection.

If the applicant re-filed the same claims that were rejected in the final rejection (w/o amending them), the examiner can issue an immediate final rejection on a subsequent RCE if he disagrees with the argument the applicant might have supplied.

The last amendment to the claims narrowed them to the extent that the patent is useless. The examiner knew this and allowed the patent.