[Warning: This story contains spoilers from Sunday's "18 Miles Out" episode.]

AMC's The Walking Dead finally delivered its long-awaited confrontation between Rick (Andrew Lincoln) and Shane (Jon Bernthal) when the two former friends and comrades came to blows.

After standing at a literal crossroads, Rick tells Shane that it's time he started respecting who the group's rightful leader is and fall in line. Shane, meanwhile, gets a taste of what it means to be a leader with a conscience when he must rely on Rick -- after nearly killing him -- to rescue him from a pack of walkers.

The Hollywood Reporter caught up with executive producer Robert Kirkman, who created the comic book series on which the AMC drama is based, to discuss Sunday's "18 Miles Out" episode, whether Shane will take his rightful place as the group's No. 2, how the reckless Shane will handle being saved by his rival and how the group will continue to learn from one another.

STORY: 'The Walking Dead' Dissection: Robert Kirkman Says Shane Isn't a 'Dastardly Villain'

The Hollywood Reporter: This episode featured some of the most brutal scenes and kills we’ve seen so far: a car running over a walker’s head; Rick shooting through a dead walker’s mouth to get to the one behind it.

Robert Kirkman: We dropped a motorcycle on a guy, what can you say. (Laughs.) You can thank writer Scott Gimple for that, he wrote these scenes. He definitely got creative and really pulled out all the stops. It's a really cool thing and you can expect more like that from The Walking Dead.

THR: Now that Rick and Shane have come to blows and everything is out in the open, what does that mean for Shane? He doesn’t seem to be like the kind of guy to go back to his pre-apocalypse days of following Rick’s lead as his No. 2 guy.

Kirkman: At the end of this week's episode, Rick is of the mind that they're square; they've got everything out in the open, they've each said their piece and they both know where each other stands, they've had their big blowout and they're riding back in that car and Rick thinks he's handled it. He doesn't necessarily think he's got his friend back, but he thinks the matters are settled. From the look of Shane in that car, I don't know that he's necessarily thinking that. For the most part, this conflict may be put on the back burner for the time being. It definitely seems like Shane still has a bone to pick.

PHOTOS: Behind-the-Scenes of 'The Walking Dead' Season 2

THR: Moments after Rick tells Shane he would have sacrificed Otis, he's put to the same test when faced with whether or not to save Shane from being trapped in a bus with walkers at the door. What does it mean for Rick now that he realizes he couldn't leave Shane to die?

Kirkman: It's a good thing for him. The fact that he can't leave someone behind and can't sacrifice Shane, despite all of the things he's done and despite the fact that he just tried to kill him, is really what makes Rick leader material. This whole season has really been about Rick emerging and proving to himself that he is the leader of this group and proving to everyone else that he can be the leader of this group. This is one more thing emerging where you see that this is a guy who can gun down people when they're a threat and can definitely handle himself when it comes to zombies but also cares about people. He's going to retain some of that humanity, and that's very important for these characters. It makes Rick stand head and shoulders above other people, like Shane, in this world.

THR: What does it mean for Shane knowing that Rick had the opportunity to pull an Otis and leave him to die but didn't?

Kirkman: Shane is experiencing series of moments that are making him question his stance on things. When Shane couldn't gun Sophia down but Rick could, that's a bit of evidence that Shane is wrong and that Rick is the right guy to be leading this group. This is another example of that. It's really going to be driving Shane crazy -- the fact that he was pretty much read his rights and needed Rick to come save him and Rick came and did that. That's going to eat away at the guy and whether or not that causes him to calm down on his position and realize that Rick is the right guy for the job, or whether that infuriates him to a higher degree and causes him to do more things to undermine Rick … we'll just have to wait and see.

STORY: 'The Walking Dead' Finds its Governor

THR: Now that they know Randall can’t be completely trusted, how will Rick and Shane move forward when considering his fate?

Kirkman: That's something we're going to be dealing with in our very next episode back: just how much of a threat this guy is and what they're going to do with him. While he did drive the car, they saved him as much as he saved them, if not more so. I don't think he would have been able to make it out of there alive. Them putting him back in the trunk, they clearly don't trust the guy to drive back all the way with him. The guy's a prisoner now and they have to figure out what they're going to do with him.

THR: A lot of the group learned from one another this week -- Andrea imparting her "choose to live" message to Lori, who then imparted it to Maggie when it came to Beth; Shane learns how to more effectively kill walkers from Rick then putting it into practice when he's trapped on the bus. How will their respective lessons impact them going forward?

Kirkman: Watching these characters learn more about this world and how to live in it, whether it's emotionally and figuring out how to cope with all of the different things you're up against or whether it's physical and figuring out how to deal with zombies on a more manageable level and how to continue to survive, that's something that they're all going to be doing at all times moving forward. We're going to see them becoming more accustomed to this world and growing and changing over time and going through similar transformations that the characters in the comic book are doing over 100 issues. You'll definitely being see more of that with all the characters -- unless they die.

STORY: 'The Walking Dead's' Steven Yeun Talks Love in the Zombie World

THR: Andrea creates a lot of friction with Maggie when she leaves Beth, who's on suicide watch, alone. How will their friction affect Maggie's likely decision she'll have to make between Hershel and the farm or going with Glenn, Andrea and the rest of group?

Kirkman: Maggie really is torn between the two groups but I'm really excited about getting to know that character and who she is. Seeing her up against Andrea and dealing with such an emotional issue was a pretty cool. We'll be doing a lot with her in the future -- assuming she survives the end of season three.

THR: Andrea and Lori's showdown over Lori's 1950s housewife mentality was insane. She can't be serious.

Kirkman: Lori is really just aggravated over a lot of things and she's lashing out. She was serious and she wants Andrea to pull her weight; certain people are stuck with certain tasks and to a certain extent people are retreating back into traditional gender roles because of how this survival-crazy world seems to work. Lori has a lot of things going on so she's definitely going to be behaving somewhat irrationally at times as she tries to cope with the pregnancy and the conflict between Rick and Shane as well as dealing with the fact that Rick was out on the road again. She's going through a lot of stuff.

What did you think of Rick and Shane's showdown? Do you think Shane is a ticking time bomb? The Walking Dead airs Sundays at 9 p.m. on AMC.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit