That's not from over watering. It could be bug damage but bugs that don't stay around. If you're growing outside you'll get transient bugs that roam around from plant to plant and don't take up residence like mites, thrips, or aphids. Those transient bugs just stop by to dine and dash. When you see the damage they're already gone. Which is why preventative spraying is a good idea. They stop by, take one bite, don't like the neem, and move on.