Amy had a reason for being snippy, Matt always acted like he was God's gift to the show.. She was protecting herself he was also cheating on her with Karyn long before they separated returning early from family trips blaming it on work.
Although hurtful Amy needed to leave to start fresh and I'm so glad that Zach found his voice and told Matt where to go and made plans for the future of his family.
Matt wanted the farm to himself, well that little control freak has what he wanted and that's all he has. And Karyn should not be opening her mouth during negotiations between father and son she is not a member of that family and Matt will never allow her to have any part of anything he has.