Sue, he used Sevin Insect Killer Lawn Granules. He has used some sort of grub control for probably 15 years and I believe he does it in spring and then again in August-September for the Japanese beetles.
I just came in from outside and tugged on the leaves like you said. None of the leaves I tugged on (green or brown) pulled out. I may just wait a bit longer on digging that clump up. Leaning more toward chemical damage like you said. Of course, dh wouldn't admit that he did anything bad or at least wouldn't remember if he did, lol.
