Put a large pot of water on to boil. Fill another large pot half full with ice water. Blanch about half the green beans in the boiling water just until tender, 1 to 2 minutes.
Remove with a slotted spoon and plunge into the ice water. Transfer to a large bowl. Repeat with the remaining beans. Return the water to a boil.
Add corn and blanch until tender but still crisp, about 3 minutes. Drain and immediately plunge into the ice water. Cut the kernels off the cobs.
Add the corn to the beans in the bowl. Add bell pepper, onion, olives, basil, oil, vinegar, lemon juice and garlic; toss to mix well. Season with hot sauce, salt and pepper.