Be very careful about letting ANYONE run your lugnuts on using an air wrench and normal torque sockets- especially if they let-er-run for a second or two at the end. This is not a case of "may damage" but of "will damage" especially with comercial quality tools which can generate in excess of 400 ft lbs of torque if not carefully regulated. In my shop we used these to shear off lugs which had been overtightened previously, essentially welding on the lugnuts. If the lugs have been overturqued and stretched their integrity is questionable and changing them all is the only acceptable fix.
This is not to condemn all use of air wrenches, use of "torque sticks" special regulated sockets, to initially tighten the lugnuts to less than the final torque specs then properly hand tightening to final specs is perfectly acceptable IMHO. Also remember that if you have alloy wheels you should always stop after 50 miles or so and retorque. Takes almost no time at all.
Overtightened lugnuts can shear off or weld on immmoveably, neither is a good or safe option.
Get a good quality torque wrench and learn to use it properly and it will relieve a lot of worry.