In a large skillet, heat oil over medium-high. Add tomatoes and cook, stirring often, until they blister, about 2 minutes. Add garlic and cook until fragrant, 30 seconds. Add shrimp and cook, stirring often, until almost opaque throughout, about 4 minutes. Add arugula, season with salt and pepper, and toss until wilted, 1 minute. Add lemon juice and toss to combine.