In a small saucepan, combine 4 tablespoons of the olive oil with the garlic. Cook over medium-low heat, swirling occasionally, until the garlic is just starting to change color, about 5 minutes. Remove from the heat and whisk in the vinegar and crushed red pepper. Let cool slightly, then season with salt and black pepper.
Meanwhile, in a large wok or cast-iron skillet, heat the remaining 2 tablespoons olive oil over high heat. Spread the haricots verts in the skillet and season with salt and black pepper. Cook, undisturbed, until blistered on the bottom, about 2 minutes. Add the snap peas and cook, stirring occasionally, until the haricots verts and snap peas are crisp-tender, about 2 more minutes; transfer to a serving bowl.
Add the shrimp to the skillet and season with salt and black pepper. Cook over high heat, turning occasionally, until just cooked through, 4 to 5 minutes total; transfer to the serving bowl. Add the tomatoes and half of the dressing; toss well. Season with salt and black pepper and serve, passing the remaining dressing at the table.