Rear Pitman Arms

Had an indy shop to install new rear pitman arms (otherwise known as dogbones) on my 1991 E34 M5 with 107K miles. I noticed the mechanic tightened the bolts with the wheel up in the air but didn't think anything of it until I got home later and read about the proper installation of the pitman arm bolts is that they should be tightened with the wheel/tires on the ground supporting the full weight of the car.

Will this cause premature wear on the pitman arms and what should I do now ? Should I losen the bolts slightly and re-tighten them with the car sitting on the ground ?