This, to me, definitely makes more sense. It would explain why Heather was upset, knowing his leaving would set his wife off and blame her for the break-up. Maybe the back and forth calls were OMM reassuring Heather that it would be safe to meet him. I don't picture him as a killer, but I can picture someone else easily fitting that role. That person, already jealous for months and possibly scheming to eliminate her competition all along, was furious her husband left her, enraged at the thought of him running to Heather, so she followed him to avenge her competition. After the fact, I think she convinced OMM to keep his mouth shut about what she did, threatening him that all the evidence points his way. I believe he may have had some role in transportation and disposal, as she already had a place in mind. Because he may have had limited involvement, he won't come forward with the truth. JMO
