In this hypothetical situation, this would be like getting two new tires on your pickup, but when you go to pick it up they accidentally put two 29" bicycle tires on your rims instead of two 29" light truck tires. They don't see the problem and expect you to drive away like this. You'd be like yeah, hmm, I see how that could be confusing, they're both 29" tires after all. no big deal, you guys take care of this, OK? you guys are totally competent enough to put the proper tires on after we've had this issue and learned from this mistake. carry on.

this would be like your plumber accidentally substituting some 1 1/2" galvanized fence post for 1 1/2 galvanized iron pipe and not noticing the difference, your electrician substituting some shit like this as a ground wire because they're both wire coated in green plastic https://www.homedepot.com/p/Everbilt-5-32-in-x-50-ft-Vinyl-Coated-Wire-Clothesline-Green-65025/202957532 and you'd be all like, yeah, no problem, I trust you to finish the job properly.

does this hypothetical drywall/tile guy just dump all his materials into unlabeled home depot buckets and drive around not knowing which of his 7 buckets is 90 minute mud, which is easy sand, which is thinset, which is grout, which is fertilizer for the roses at this one customer, this one bucket of diatomaceous earth for his swimming pool gig, and this one is calcium chloride, for when its snowing...

I agree with the other guy. If a "professional" made this error and managed to do several square feet of wall without noticing, every single other thing that "professional" has touched is now suspect. This is the same level of fuckup as a body shop using house paint on your car.

Pre-mixed mortar or mastic only share a color with joint compound. Aside from that they have all wildly different textures and smells. It is hard to mix them up if you've actually used them a few times.