Carol's "admission" isn't nearly the same thing as either T-Dog's or Aaron's.
First of all, Carol killed Karen and David and concealed it!
Carol didn't admit to shit until she had her back to the wall and had to with Rick
Rick asked a question, but he had no evidence at all--just a hand print, which could have been produced from any number of people in the prison who were still able bodied. Carol answered a direct question because she was being honest.
and she only admitted what happened to Tyrese because of the emotions of that day (the death of Mica and Lizzie.)
She did not have to tell Tyreese anything at that point. They were both devestated enough about the Samuels sisters, so she could have dealt with that matter independently. It was her own sense of honesty that was wearing on her throughout
"The Grove," (
before Mika was murdered) as she could not look Tyreese in the face, with his professed trust, and not know what was the right thing to do. Further, when she admitted her role,
she was willing to accept whatever his response would be. Tyreese forgave her because he understood why she committed the act, which was not out of malice, insanity, or anything other than the protection of the prison population.
She also did it to two people who were isolated and presented no present threat to the rest of the prison's community.
Was the cell Karen and David occupied locked? If not, that means if they turned, they could get out and attack anyone. From episode one, we already know walkers know how to open doors (Morgan's long dead wife still turning the doorknob), and push it aside. The mass reanimation in the prison (season 4) illustrated that the untreated were almost guaranteed a death sentence.
T-Dog accidentally dropped the cuff-key and it just happened to fall down the drain and he had to get out of there. He admitted it right away, it wasn't something he could be directly blamed for as shit happens.
Of course he could be blamed for it, which explains his nervous behavior when the group discussed how to tell Daryl (still on his food hunt). Moreover, after discovering Merle's hand, Daryl aimed his crossbow at T-Dog.
Blame, not
"shit happens."
The same as Aaron--it is not
"shit happens" to drop what amounted to intelligence information on the ASZ. Carrying that around--and trying to be cautious was his job, so it was an acknowledgement of the risks. He would be a most slithery character to not admit how the wolves found the ASZ--and that's only reason the Wolves' pack discovery--and Aaron's confession were shot at all. There's no need to shoot extraneous scenes.
T-Dog couldn't help what became of the key when he fell, Rick made the decision to lock up Merle.
There was a bag of tools there. After losing the key, he could have grabbed pliers or that infamous hacksaw and set Merle free. Before anyone says,
"he had to get out of there," then that speaks to a very selfish choice to leave someone behind--even as he chained the door.Let's be clear,
he never said he chained it with the intention of going back to rescue Merle (since the group's own escape from the store / survival was in question). So, locking Merle on a rooftop several stories high did not leave options (from T-Dog's POV) of escape.
...but at least he admitted his guilt--as he should have--just like Aaron.