By "death sentence", are you suggesting that the candidate will never again be considered for a role at Google, or are you just saying that they're not going to space today?

Being rejected at an interview at Google means you have a one year cool down period. You can try again then (or they might call you back themselves).

They called me back 6 month after first rejection. Going for on-site to London in a week.

Thanks. I've turned down a couple interviews knowing I'd bomb at least one, didn't want that on my perm Google Record. It's nice to know it's not just me, and also there's redemption.

This is a bad strategy. One thing that actually helps you tremendously is evidence of growth. The easiest way for the hiring committee to see this is for you to show improvement from a previous interview.

I guess it'd be possible to game this signal, but that's a lot of effort and still just one signal.

My real point is that it absolutely does not count against you.

Fair enough, and I agree to an extent. But when I got that packet of prep material, I froze. I may go down that road again in the near future, but I want to be mindful of thresholds.