There was a time the tabs didn't come on replacement windshields but now they almost always do. He may not have much experience at this.
Gluing a tab to a NSX windshield is no different than gluing a tab to any other windshield.
Far as I can see they don't make a California version as the VOC content is so small.
Something's not right if a simple thing like gluing a tab on a windshield isn't going well.
Try someone else.
He is a pro and came highly recommended from a solid bodyshop. He installed a new windshield on my aunt's 07 S500..it was perfect and very clean. Also, he even does custom windshield glass for West Coast Customs. I think he had a bad batch of glue or it was old. I also think one of the efforts failed because we didn't let the tab dry on there long enough. My stiff suspension caused it to knock off. I also have 435rwhp so the torque isn't helping either...LOL. Regardless, it works now with the H. Depot epoxy and putter trick.
Jeff