WJA,
I think it's safe to say that anyone going thru this application process is pretty experienced and, for what I have seen, most of us come from "very respected, safe and strict SOP" airlines.
I have friends that failed the assessment that were even more experienced and more qualified than others than passed, but didn't have a good day I guess. So it's life.
I also said to myself that I was thru with the process after we failed the check. I figured the job would be too risky for me to leave my present gig.
But after receiving the email to resit the test I think I'll wait and see the impressions of a few colleagues that are already in or joining soon and then make my mind up.
Right now I have nothing to lose by trying again, so I think I might give it a go...
Have you got a joining date yet?