Probably waited 3000 miles or so and than went back to synthetic with a more competent service station.

Got another 100,000 or so miles on camry so apparently no harm was done

So they either threw the bottles in the trash or as they said in the drain rack so your bottles had not left the site yet so where did they put them? I could see them not doing the service behind the curtain if it was their product but using yours and not possibly doing it makes no sense. I might have a discussion with the manager to do it again with their stuff?
On a side note similar thing happened to me years ago I took my car into a retail auto place for a coolant flush/change. I watched from the observation window as the tech pulled the car into the bay, opened the hood and proceeded to suck out the overflow tank and then added new coolant to the reservoir, put the hood down and pulled the car out, done. I was in total disbelief as they never opened the radiator.

What did you do than?

Binging your own fluids
 

I use Sumter Tire. I bring my own fluids and they always return the partial empty container without asking. I hate to recommend them because they have gotten so busy it increases my wait times. But they are as honest as I have found.

Dealers rob us and those quick lube places can not be trusted. Best to find a local shop you can trust.

I also am a DIYer, how do you change your tires?

I am not a DIYer for vehicles. The only thing I change on my vehicle is wiper blades, which I buy from Amazon.

Here's a vid (if TOTV lets it be put out here)of how to change a tire without a machine. NOT worth it IMHO!!!!
https://www.youtube.com/watch?v=k1Feg5CbMp0

Honda doesn't manufacture any lubrication products. Valvoline, however is one of the BEST oils or grease that your money can buy. The techs may be stupid, but if they used Valvoline, I don't think you need to worry.

Thank you. I really appreciate the answer.

Do you find one location better than the other?

Dealers often don’t use factory fluids. They will use a ‘rated’ fluid. My old local dealer used a generic 55gallon drum of engine oil that met the requirements.

Sumter Tire
 

Reminds me of the movie “The Fight Club”:
The first rule is: “Don’t tell anyone about Sumter Tire”.
The second rule is: “Don’t tell anyone about Sumter Tire”.

But, made to Honda’s specifications which may or may not differ from Valvoline?

Yep and the pump it in using gauge on pump and some over fill and don’t even check level after the service.

I have no problem with Valvoline products , and as you say their product will probably do just fine , however if I go the extra mile and pay for a premium product that's what I want, thinking on it I should have broken the seal myself, once the seal is broken it would be hard to resell, next time there will be no problem as I will be doing it myself, if I am lucky maybe they will cough up two bottles of Honda Dual Pump Fluid ll