For the salad: In a large skillet, heat the oil over medium-high heat. Add the garlic and cook until fragrant, about 30 seconds. Add the tomatoes and red pepper flakes and cook for 2 minutes. Season the calamari with salt and pepper and add to the skillet. Saute, stirring frequently, until cooked through, about 2 to 3 minutes. Drain the mixture in a colander.
For the dressing: In a small bowl, whisk together the lemon juice, oil, capers, and lemon zest until smooth. Season with salt and pepper, to taste.
Transfer the calamari mixture to a serving bowl. Pour in the dressing and gently toss until all the ingredients are coated. Garnish with chopped parsley and serve.