I think they have to some how make a TV program so they made her that dumb.
But I agree to you as per TV Serial story flow, that Lori and rick need to pay attaetnion to their Imp child roaming all aroung getting others killed. If daryl comes to know of what carl did surely he is going to be the badest ass ever on The walking dead.

 

Why is Lori required to have her eyes glued to her 12 year old son, who is supposed to be upstairs? HE SNUCK OUT! Why is that Lori's fault?

 

I'm not sure if you get the point Duzy and others (like myself) were stating. This is a Zombie Apocalypse - aftermath.
If Lori wasn't a complete bitchy, selfish wife and MOTHER... maybe she'd keep an eye on Carl 98% of the time instead of 10%.
Therefor it is indeed LORI'S fault for Carl's absence. He's a young boy - without rules/adult supervision, young boys will step outside the 'boundaries'.

 

I don't think it was Carl's gun, don't you remember Shane's gun going off when he got stabbed? The stab must've made his fingers reflex and hit the trigger.

 

Carl just has to be Wesley-freaking-Crusher. Getting them into and out of terrible situations with maximum red shirt death.

Kid needs a leash. At least he realized that Dale's death was his fault. Stupid adults for lying and telling him it wasn't.