And here is the rest of the story.
After driving about 100 miles with no engine light appearing, I made my way back to the repair shop for a refund of the diagnostic test fee. Keeping my cool, I explained at detail my experience, the office manager not only refunded my $75. but took me back through the shop to meet all the techs, got an apology from the tech that misdiagnosed the car. He said he would be extra careful next time and have a second opinion on any future fix.
Then the manager took me aside and assured he would never be put on my car in the future.
I think my *** was appropriately kissed.
And yes I will go back as they were highly recommended.