See? That's how the game is played. By raising doubt in your mind. That's the big mind F--k: Who are we to know? Who are we to judge?
BTW, auto repair is not a "profession". It's merely a trade - and it's often a dirty business, in more ways than one.
I will say it is not the truth, and if you don't like my opinion which is based upon experience, I don't care whether you agree or not.
Can you be like a smart fish, and spit the hook out of your mouth before you get hauled in again? Or do you now want to be hit up for another $25, in addition to what you've already spent? Even if it did prove something, at this point, what difference will it make?For $25 plus shipping, you can have Blackstone Labs analyze this tranny oil (there are probably other labs who also do this same thing). That report should come back reading that the fluid is basically in like new condition. So if the report comes back looking like old fluid, it means either they stirred up a bunch of nasties with the flush and didn't clear them out, or else they didn't do the work at all.
And (if it did come back bad), with a negative report like that in hand, even their best dealer dance couldn't get them off the hook.
JMHO, but without a lab report, it's all just speculation.
Regarding transmission fluid, all you need to do is to use your eyes and your nose to realize the truth. Or you can throw away another $25 (plus shipping...). The choice is yours.