The info I heard is that Apache refused to get specialist advice (they don't have an air advisor) and were only interested in whichever operator spoke to them last. BRS seem to have filled that gap but Apache have a reputation for not paying that well so this might be a case of BRS picking up market share but not profit.
Most metrics would have the 175 very slightly ahead of the 189 on technical assessment so obviously something to consider if BRs do win it with a 189. As Mitchaa says, Airbus have a reputation issue.