Dropped third strike is not always easy to see. Maybe he missed that portion of the play. I have.
His later comments may just have been to defend himself.
Sounds like it wasn't a great day for him.
Had a game last week... third strike looked caught to me - ball was outside and a foot above the ground. Batter takes off; they often do. I say "Batter's out. She caught it." I say it twice. Runner continues. Catcher throws the ball. Runner gets on base.
I ask my partner, "She caught the ball didn't she?" He says No it came out! Apparently she dropped it as she raised up and smoothly picked up to make the throw. We let the runner stay on base. Defensive coach complained a little but acquiesced in the end.