Frisk was reading the news. Papyrus apologized for hurting children, stating he didn't know what happened to children sent to Asgore, and many monsters may have not either.
He figured the children died by natural causes. Papyrus was proud of his lie. He never killed a kid, and never intended to. After all, the best lies were based in truth, even ones based on a technicality.
He figured being a man who did nothing about a human would be a problem in the long run, he only got the sentry job to get Sans out of the house. The man was becoming emotionally numb due to the resets, and this let them both see who was the likely cause.
Okay, it backfired with Charlie. That's why the puzzles were tamer now, or not activated at all. He really hated Sans. He was hated too, but Sans had most of their hate. But you live and learn. Though,Sans' promise made Papyrus nervous as he doesn't trust any anomaly ever since Charlie snapped.
Monster Agrees Wrong Was Done
Local monster Papyrus agreed that Frisk's journey in the Underground was unfair. "I never knew they were going to be killed." He states.
Looking at his puzzles, they aren't dangerous. Us reporters asked this monster about them, "Well, kids like puzzles right? I just wanted them to have fun!" This man seems to not to have known these puzzles are dangerous to humans.
"If I knew, I would've walked them to the surface myself. I'm sorry." We suspect his brother, child murderer Sans, was aiming for his next kill, planned these puzzles, and made them less dangerous than normal to convince Papyrus they were safe.
The one Papyrus made, but deactivated may have been made with his brother's help. Did his brother use him?
Even when the human was limping to the "prison", they were always coming out of it in full health. Maybe this man was pretending to put in an effort due to Sans' insistence.
Maybe we should reconsider our hate for some monsters who may have been lied to.
In Sans' cell, his cellmate laughed, "Still not buying it. Good for him though." Sans was stretching his neck up to see what his cellmate was reading. "About your brother." The newspaper was tossed on Sans' head.
He read it after mumbling, "Thanks." His eyes darkened. "I'm not manipulating my brother!" "I already knew that. Not that I put manipulating people past you." "Guess at least it may help the free ones." "May help you too. I seen people worse than you get lighter sentences, or let off completely." Dillard laughed, "And I don't believe your brother one bit. But I'm the crazy one." Long as you don't have a knife, thought Sans. "However, I do believe in good people in bad races." Dillard was now using Sans' skull as a footstool. "Grillby for example. He likes you because your race has no concept of good friends." "Excuse me!?" "You know it, skeleton. But he takes care of Frisk well, because he's good at heart." What kind of backwards logic is that? "Racist. Probably. But I'm still the crazy one. And luckily for you, I'm not allowed knives." Thank goodness, Sans thought.