Absolutely thrip damage, 100% for sure. I've been growing for 22 years and I've had thrips, aphids, mites, you name it. That IS thrip damage. I know these plants have already been cut down and harvested, but just for future readers, that is thrip damage without a doubt. Set up yellow sticky traps around the garden, apply neem oil, and introduce ladybugs when the thrip population are low. This has solved my issues and many of my friends issues, and completely eradicated them, every time.