Just bill at your normal rate. My guess is there will be extra in the payment. If not you did the right thing.
I had something similar happen. Custom calls me shitfaced drunk from China. Makes about 60k in upgrades. The next day I send him an email with the requested changes. He says I don't remember calling you. But if I was drunk and cakes you about it. I really must have wanted it.
We did may houses for this guy. All 200k plus projects for just theaters ....
I can't even count how much funny money and perks this guy gave me and my guys.
Ed will be known as the Tiger Woods of the integration business, followed closely with the renaming of his company to "Hotties A/V". The tag line will be "We like big racks and tight holes"...