Official statement:
Amazon S3 Availability Event: July 20, 2008
Peter Vosshall in the video below says
… it took down s3 completely. So one server, one NIC, one bit, took down our regional service and that was the only layer - we had checksumming all the way up and down the stack - that was the only layer that didn’t have the checksumming.
As seen on HN:
Reminds me of a rogue NIC, flipping a single bit every now and then, that took down S3:
