Jack Twist: God, I wish I knew how to quit you!
Ennis Del Mar: Well, why don't you?
Ennis Del Mar: Bottom line is, we're around each other an' this thing, it grabs hold of us again at the wrong place, at the wrong time, and we're dead.
Jack Twist: That's more words than you've spoke in the past two weeks.
Ennis Del Mar: Hell, that's the most I've spoke in a year.
Answer: Lureen may have been lied to about how Jack died. As a kid, Ennis had seen the body of a man that was killed for being gay. Knowing that Jack was 'seeing' other men, Ennis knew that he must have been killed for that reason instead of the way that Lureen explained it. Even if she did know the truth, she may have lied to him because she didn't want Ennis to know how Jack really died.
Jane Doe