Youngest sibling Casey is facing a murder charge on Australian screens this week after shooting dad Danny (Andy McPhee) when an armed robbery went horribly wrong.
The scenes, which are yet to air in the UK, saw Casey make the drastic decision when Danny ordered him to shoot an innocent man.
While Brax accepts that Casey had no choice but to stop Danny in the high-pressure situation, Heath is finding it much harder to forgive his brother.
Dan Ewing, who plays Heath, told TV Week of the storyline: "Heath had a lot of questions for Danny, so it creates this massive conflict between himself and Casey.
"I think deep down, Heath knows it's not Casey's fault as he didn't really have a choice - it was shoot this poor bystander or shoot dad. He had to make a call and he made it. But Heath being Heath needs to blame someone, so let's blame the little brother."
Speaking of how his character defends Casey, Brax actor Steve Peacocke added: "Brax knows deep down their dad was a scumbag who risked ruining Casey's life, and he wants Heath to see the facts in front of him, instead of being blinded by what he thinks has gone on.
"Heath's relationship with Danny was different, but the family needs to be united behind Casey, because the dad's gone and it's Casey's future at stake."
However, Casey will be left distraught when Heath vows never to forgive him during a heated argument.
Lincoln Younes, who portrays the teenager, told the magazine: "That cuts Casey very deep. Not that he ever shows much love for Heath, but there is that affection towards him and they are family - and to hear that said from someone so close to you, it's very hard for Casey to hear those words.
"The main reason for the dad being introduced to the family is because Heath wanted it and instigated it - and then, in Heath's mind, Casey took away that opportunity. Heath is in denial about what his father was really like."
Home and Away fans in the UK will see the shooting plot on Channel 5 in October.