please note this post makes reference to the Jan 20 episode on CBC
It seems that all's well that ends well for David Platt. After almost killing his brother and being banned forever by his family, he was exiled to the barren hinterland (Audrey's house - ed) and condemned to live in shame for the rest of his life.
That lasted for about two weeks.
Now Davey is back living at home just like BTTKN (before trying to kill Nick) with Kylie and the kids while his loving Mom looks on.
It's not the first time that Psycho Boy Extraordinaire has wriggled out of the consequences of his heinous crimes. There are too many nutbar episodes to recount here but let's just say he's almost killed/maimed a significant percentage of people on the Street (Jason, Bethany (his niece), Gail, himself, Graeme, Nick). After every wingnut episode, Davey is first ostracized then quickly forgiven by the Platt clan.
Why, you ask, did they let him off the hook for trying to kill Nick? Apparently he's a great dad and really good with Max and Lily. That's like saying Hannibal Lecter was a great chef. Davey may be in his cuddly, contrite phase right now but just you watch. It's only a matter of time before his true psycho personality returns.