In one scene, after they leave the restaurant without paying, the owner shoots their car's right wing mirror. Later, in the scene when the truck is ramming them, the mirror is intact.
The UN mission ended in 20 December 1995 when NATO took over (IFOR/SFOR). In 2000 there should have been SFOR flags instead of the UN flags, SFOR patches, not UN and no blue berets. Military vehicles should have their national camouflage painting and SFOR markings. This is for NATO/SFOR details. The UN Mission (UNMIBH) was still active during the time this film depicts and the UNMIBH personnel and equipment are accurate - specifically the blue berets and UN vehicles for the UN International Police Task Force personnel in Foca.
After they got shot by the waiter, Simon was asking Duck about paying taxes to Bush. As the story happens in Fall 2000, George W. Bush wasn't yet the US president.