Well, except for that dead kid.
I'm of two minds when it comes to how "Breaking Bad" uses child endangerment as an emotive battering ram, its top gear in terms of terrible consequences. It's effective -- of course it is, it's brutal -- but it's also a well to which the show goes fairly often, from the neglected offspring of the two addicts in "Peekaboo" to the unseen owner of the teddy bear floating in Walt's pool after the plane collision in season two, from the 11-year-old gang recruit Tomas to Brock's getting poisoned as part of Walt's plan to get Jesse back to his side.
In some ways, "Breaking Bad" has been about engaging with and knocking down the idea of children as untouchable things that everyone can agree need to be protected, or at least the idea of what that protection means. Some of the show's worst or most regrettable behavior has been in the name of sheltering and providing for kids, a theoretical positive that has foremost guided Walt's descent into meth production and violence for the sake of, as he's so eager to point out, his family.
Skyler (Anna Gunn) has gotten trapped -- "I'm not your wife, I'm your hostage," she says to Walt in this episode -- by her desire to keep Walter Jr. from finding out that his dad's a criminal. Even Mike had been stockpiling money in that account in the Caymans under his granddaughter's name, though when given the chance to flip in order to save some of that cash for her, he still thought it better to walk away.
So the nameless boy we see riding his dirt bike out in the desert and collecting a tarantula in the cold open has the misfortune of coming across Team Vamanos Pest as they're finishing up their deed, one that needed to remain secret in order for them to preserve the lives of the guys on the train. Todd shoots him (and there's something particularly rough about seeing Landry from "Friday Night Lights" unhesitatingly kill a kid) because he's been told no one can know about what happened, and because he's eager to prove himself a valuable member of the crew. While Jesse's impulse was to try to stop him, if Todd hadn't done it, someone else might have had to -- maybe Mike, maybe Walt, because their whole ungainly plan was centered on staying undiscovered, and it's all too easy to see how the situation could have turned into a kidnapping, a prolonged argument over what to do next and an even more painfully premeditated murder -- Gale times one thousand.
But that dead child promises a world of knotty complications to come in the series, another symbolic sacrifice on the altar of the drug business and one that could potentially drive Jesse away. And as we saw again in this episode, he's the necessary stabilizing factor for Walt and Mike to work together -- they need to keep him, but he has the least reason to stay, and he's not going to like this at all.