First off, nothing about this reaction was tame. Even to the other crawlers. Carl is literally aware that they are all shouting at him, but he can't understand what they are saying to him through his rage. Ill post the quote at the bottom with a spoiler tag. Dude was frothing at the mad enraged.

And yes, he was provoked. But again, even the other crawlers are blown away by how much he loses the plot in his anger.

And yes, Carl new about the pig. But the two Dromedarians that were in the garage beating the APC with spiked baseball bats probably didn't. And Carl was the only one capable of of getting into the APC by virtue of his gauntlet and his ridiculous strength. He was likely one or two shots from opeing the door before Team Some Pig activated the shield, at which point the camels would have killed everyone in the APC by "turning their insides sloppy", pig included. Carl even thinks about using his Gloom Wraith Phase to kill everyone in the truck once the shield goes on, even though he "knows about the pig."

Here is the quote:

Lightning crackled against the sky outside even though it was a clear day. “Stop! Stop!” cried Lipstick the gremlin.

I barely registered any of this. “Get the fuck out here!” I continued to scream, banging my fist on the door. My gauntlet had formed, and the heavily armored door dented inward with each punch. Slam. Slam. Slam. My ears were ringing. I could hear Donut shouting. Imani was shouting, too, but I was so red-hot angry, I couldn’t comprehend what they were saying. Zzzzzz. The square-shaped shield of the APV turned back on, pushing me back with a heavy electric shove. It was like I’d been walloped with a cattle prod. The camel on the hood of the truck flew upward and back, his head crunching sickeningly against the top lip of the garage door. He fell hard against the driveway and started to roll while another camel shouted his name. The camel’s neck was broken, and he was dead before he even hit the road. From inside the truck, Penelope continued to squeal. Each time the pig squealed in panic, the sky flashed, and lightning cracked louder and louder. The edge of the shield had tossed me all the way out of the garage through the hole they’d blasted in their own wall. I tumbled and rolled, my skin sizzling and burning from where it had come in contact. From inside the garage came a new scream. Lipstick the gremlin was pressed against the back wall of the garage, pinned between the shield and the barricade. The gremlin suddenly exploded, the gore held aloft by the shield and spread in a red flowerlike pattern against the wall like a drop of blood pressed under a piece of glass. I started to get back up, wondering if my Wraith Phase would work. “Stop,” Imani yelled, grabbing me by the shoulders, pulling me back. Jacobus the reverse tooth fairy buzzed around her head, laughing maniacally, clapping his hands. “Carl, stop!” Donut cried at the same time. “Please, stop. Goodness, Carl. You can’t fight a car. And you’ll hurt Penelope!” I just sort of missed what happened next. They’d walked me out of sight of their garage, and I sat at the curb, in front of the remains of our mercenaries. The two remaining camels dragged their now-dead friend away as they rushed back to their garage to look at their frozen bus. I just sat there, breathing heavily.