"...wouldn't the prints that were shot with AdobeRGB, yet printed as if sRGB look washed out overall, across all/most colors in the color checker?"
There are so many ways Gary can sabotage or handle the data incorrectly, anything is possible. And again, you don't print as sRGB. You could assign sRGB to Adobe RGB (1998) data which would be an incredulity dumb thing to do and yes,
the data then converted to the output space would be wrong.
Just go into Photoshop and Assign the wrong profile to any document and see the results. The numbers don't change, the meaning does. Leave the incorrect meaning and then convert to the output color space, the output would be wrong. Again, you'd have to go out of your way to do this and it's an incorrect way to handle the data. If you had a document sized for a particular output size and resolution, then resized down using the wrong algorithm 500% and printed it, it would look pretty ratty too.
Don't handle the data incorrectly! And if you do, don't blame it on a color space or a resize algorithm! It's your own fault.