Two questions about the blackmail plot
1. Douglas tries to hire Mortensen to murder his wife. Mortensen tape records their conversation, then uses it to blackmail Douglas. But if you recall, he waited until AFTER the attempted murder to blackmail Douglas. Why wait till THEN? I mean, after you walk out with the tape, you are sitting pretty. Why not leave, call Douglas ten minutes later, play the tape for him, and say "Ok, Steven. I now OWN you. That'll be my 400K plus whatever more money I feel like squeezing from you till the day you die." Yes, I know that no murder attempt would have been made at that point, but still, you've got Douglas on conspiracy to commit murder. At the very least you've got enough to destroy his reputation and make his life very uncomfortable. So why not blackmail him THEN?
2. When the two meet so Douglas can pay off the 400K in hush money, Mortensen extends his hand. Douglas pauses for a moment, smiles and shakes Viggo's hand. Some might wonder why anyone would shake the hand of someone who just blackmailed them. My take was that it was an acknowledgment among thieves. It was the two of them saying to each other "We're both scumbags. We both know it. We both deserve each other." Anyone else agree? A different take?