Also had that problem, in fact have been working on it for over a year and can finally walk in and out, around the blind, touch the dog, etc without it effecting the guarding. It mainly took time, and making sure helpers did not do the things that caused the issue in the first place.
Liesje & the K9s
Nikon (GSD) U-CH SG Alta-Tollhaus Bono SchH1 KKL T1 FO PA TF-III FDCh-S CL1-R UJJ U-CA HIT TT CGC
Coke (All-American) VPC's Coca-Cola CGC, couch warmer extraordinaire
Indy (All-American) Blue Horizon's Indigo Girl, flyball star in training
Rainbow Bridge Kenya (GSD) U-CH Alta-Tollhaus-Krieger Lamb Chop CL1-R CL1-F RA HIT TDI TT CGC
vom Blauen Horizont / Blue Horizon GSDs