So, what does it mean that this was, supposedly, a verifiable election?
It means that you can go to the audit web site. There, you’ll find a detailed specification that describes the file formats, encryption mechanisms, and process by which you can audit the election. You’re able to download every encrypted vote. You can verify all of the vote fingerprints by recomputing the fingerprint yourself. Each voter can check that their ballot is on that list, under the correct voter identifier. Then you can check that the encrypted tallying was done correctly, simply by recomputing it. And you can check that the decryption proofs check out.
And in the end, you can declare, with full confidence, because you coded it yourself and ran the code yourself, that given the published list of vote fingerprints, which individual voters checked, the result of the election was correctly computed.