Relevant rules for Ballistic Reinforced Armor special:
Ballistic-Reinforced Armor (BRA)
A specialty armor developed to counter projectile weapons
and missiles, ballistic-reinforced armor reduces all damage
delivered by attackers that make use of the AC, IATM, IF,
LRM, or SRM specials, by half (rounding up). This reduction is
applied whether the attack is delivered using the unit’s normal
damage values, or by just the listed special abilities.
Thus, if a unit that delivers normal attack values of 5/4/2,
with an AC2/2/0 special, delivers a successful normal attack
against a unit with the BRA special at Medium range, the
attack will be reduced by 1 point (half the AC attack value at
Medium range), dropping the normal total of 4 points to 3.
The issue: The example does not illustrate what the rule says.
The rule says
all damage is reduced, not just the damage value of the qualifying special(s). By the way the rule is stated: if the 5/4/2 damage array satisfies the binary condition of having at least one of the AC, IATM, IF, LRM, or SRM specials, then all damage is reduced by half (whether or not the damage is dealt via special attack)... meaning the medium range damage should be 2 rather than 3.
The question: Does the rule need a rewrite to match the example, or does the example need a rewrite to match the rules?