I am pretty much this was because of fat fingers, but how an earth there's no security measures for this kind of thing? It's 2020 already and after seeing this kind of mistakes, i am pretty sure that ETH adoption is further away. Just one warning message informing about the possible huge mistake could have saved millions for this guy.
wow,, just sent about 0.55 Ether with Transaction Fee: 10,668.73185 Ether this is really big mistakes , thats why people should double check their transactions before send it