Tom invited his own 'Fate"with his stupidity and bad judgment
-Tom should have gone straight to the police when he found Hasekell was dead. An autopsy would have supported his claim that Haskell was already dead when he hit his head on the road when Tom opened the passenger side door. Of course then he wouldn't get to keep the $700 and the car but it would have been much better than becoming a murder suspect. (He even tosses his own stuff out alongside Haskell's body, so that it could be identified as his own!!!! How was Tom planning to live on with identity of someone officially dead??
-Tom should have never picked up a hitchhiker--attractive female or not--and further complicate his already complicated situation. After all, he was driving a dead person's car under fear of being suspected as his killer.
-As soon as he realized that he had made a mistake by picking up the woman ("Vera"), he should have contrived to somehow get rid of her before she complicated the matter even further. There are so many ways to think of that he could have dumped her by the roadside. It was extremely stupid of him to try to explain what had happened (very likely even revealing his real identity) to her, the dangerous character of whom should have become apprant the moment she started to try to blackmail him). It should have been obvious to him that Vera herself was running away from the law and she would have never contacted the police even though she kept threatening to over something that she had nothing to gain by doing.