looks like www.amazon.com is down due to DNS failure

Name servers refused query (lame delegation?) [205.251.197.124, 205.251.194.41, 2600:9000:5301:dd00::1, 2600:9000:5302:2900::1, 2600:9000:5305:7c00::1, 205.251.193.221, 2600:9000:5307:5900::1, 205.251.199.89].

whois / host records point to dynect.net and ultradns.(net|co.uk). But per HN 2016 that is their failover, so it's expected behaviour? https://news.ycombinator.com/item?id=12762915