Tom's Goal, and his method
Seems like Tom was loyal to Leo and wanted to save/protect him from Casper. Tom also knew that Bernie was a lying troublemaker and wanted him gone.
So far so good. Tom comes up with a very convoluted plan to accomplish all of this.
Why wouldn't Tom just kill Casper, Bernie, and the Dane? He had them alone many times, so getting to any of them was not a problem. He killed them later, so why not earlier?
I can see WHY Tom wanted things to end up like they did, but the goal could have been accomplished so much easier.