Hey I have done the same thing last night. To the same guy! With the new update it autopopulated. I sent 484 steem across. This has only happened with the new update as in the past I have always wrote it in manually.
I have sent a message to the page who has made one post and they are yet to respond. Steemit has also not response yet?
Hope I get my funds back as this is almost 1600 USD
RE: Sent 147 Steem to the Wrong Account! Public Service Announcement