(Nearly) all valves have a min/max value that will still allow the trim to fit, and the handle still work. If it works, it is likely within the manufacturer's specifications. The range can be over an inch, and personally, I prefer it to be closer to the wall, but given there was little to any room to work, sounds like it is in the wall and working within the specs...if you wanted it in a specific place, it would have had to have been stated before the work was done as it sounds like it is okay. It may be impossible to move back without cutting a bigger hole, which you specifically didn't want. Sounds like he did a good job given the circumstances.