I don't agree. You both tried it didn't work, and of course he worries over the kids. That's a hard attachment to make and he may feel bad because they may have been hurt. That's normal, and he isn't a bad guy for it.
NOW, stop the contact, and speculation and blame game. While anger is a part of healing/mourning, don't hold on to tightly to it.
THE HEALING PROCESS
7 STAGES OF GRIEF