for all that the father is absolutely useless and worthless (or somehow the kid anf mother has forgotten to mention their treatment? though that can't be it as if nothing else his informants uld have informed him), I find it even stranger how the kid thinks he is disallowed from retaliating when they storm into his house and treat them that way.
As a 6 year old there is absolutely no issue with "acting temperemental" when treated that way, as at most you would get disciplined slightly - but at the benefit of them no longer treating you like that if you repeat it often enough. (might want to make sure the real events spread properly though, to avoid gossip labeling you as the aggressor).
And when they broke into his room and stole his present, he even had the chance to bring in the judicial system if he truly wanted to humiliate them in a M.A.D way (won't actually win the case, but its existence is enough). Or, yknow, he could've retaliated in other ways if he wanted to. Either way, no reason to just suck it up.