Beside seeing your own password, when you think about it it's pretty obvious that guy is just bullshiting you and he doesn't have any "incriminating" stuff. If he really had access to the your computer he would see that you know thing or two about the crypto so he wouldn't explain to you that BTC part, or he would provide more evidence. This is just generic email (except your password) sent to probably thousands of people, and unfortunately some will fall for the this.
It makes sense, if he could control access to the victim's computer, then nothing would be left. The threats given also appear to be general words that are not specific to the victim. These hackers just send SPAM emails for a lot of emails and are just bluffing. Maybe he got the victim's email from some bounty participant database or some other list. some people will believe this e-mail because of the same place and event, but only a very small possibility.