the little boy sees his sister getting literally eaten alive by their dog and his reaction is like ohhhh weirdddd, what is this? whats going on here??? how peculiar! then only starts reacting naturally by screaming in horror like 15-20 seconds later
the dad, seeing his small son being held by his demon possessed dead wife, whom he watched die, doesn't IMMEDIATELY try to get his son back and instead watches the demon-dead wife slowly back up to a ledge and jump off
in the final act as they're pulling up the rotten one, surrounded by children that they know are possessed by demons, with the elder demon-experienced lady telling the dad not to listen to the demon spawn, decides to listen to the demon spawn to go get an axe that isn't there, resulting in insta-death for the lady. durrrrr
fuck, yet another one - the dad just sitting there blankly and doing nothing while the nurgle baby walks out and runs his hand over his head. a natural reaction would either be shrieking in horror and running or going primal and trying to rip the child limb from limb.