I can see very easily how the road calipers could be installed mistakenly. The boxes (road and MtB) are identical but for a small label difference. The supplier part numbers (if the brakes were special ordered) are often virtually the same and often are adjacent to each other. It's a simple oversight to pull (or pick) the wrong one off the shelf (or into the on line cart). Often the person who picks the box is not the mechanic that installs the caliper. And until the new SL version of the BB7 came out the calipers look the same out of the box.

But what I have trouble with is that the mechanic didn't notice the lever/pad action was other then usual and that the stopping power was almost non existent. The QC part of the service loop went awal. I bet the mechanic or service manager didn't do any pad bedding in during the test ride. I wonder if a test ride was even done.

This is why I said that the LBS needed to explain how this happened. Not so much for the OP to learn why BUT MORE for the next customer to not have the same mistake happen. The shop needs to have a better check and balance system for the repairs done.

Perhaps the work was done "on the spot" while the OP was waiting. Perhaps the shop was very busy. Perhaps the mechanic was distracted. Perhaps the wrench was not experienced with disk brakes. But the shop needs to have a QC in place to confirm the end results of their service.

This is one of the reasons that i have always not liked doing service work while the customer is waiting. It sets up a expectation or standard of the amount of time the service takes (being what makes the service "good") instead of the quality of the work done. Of course some service (like flats) need to be able to be done ASAP. But the more involved work is usually better when their's no customer looking over the shoulder or pacing around the shop.

I don't know if my comments were what was going on in this case. But I wouldn't be surprised if some combo of the above was involved. Andy.