If you "do it right", Yurik should stay in some kind of surrender mode which means the bandits won't shoot him. Only you coming close enough to him will trigger him to "activate" and thus become a valid target for the bandit's violence.
See if you can draw the bandits out to come and face you and eliminate them all before you approach Yurik.
I usually go in the bed of the truck and fire over the two crates in the back. The first time I encountered that situation, Yurik did more damage to his assailants than did I- he's a bit sneaky...
"On the bright side, after the Armageddon there'll be PLENTY of work for LIQUIDATORS..." -RAbbi
"There are OLD stalkers and there are BOLD stalkers, but there are conspicuously few OLD, BOLD stalkers." -RAbbi
In all versions of SoC I always "break" the battle between Yurik and the trenchcoat Loners by carefully avoiding the trigger area and killing all of the bandits who attack the scrapyard, then talking to Bes for mission completion. As soon as Bes gives the reward, the would-be Bandits and Yurik then simply put their weapons away and go about their business. In vanilla SoC they invariably will stay in the Garbage until their inevitable demise, but one time in ZRP, this happened: http://imgur.com/QetYu8g