The choice basically came down to promised in-support costs. Airbus 'somehow' (cough, deliberate under-bidding, cough) managed to grossly under-estimate both the operational costs and development maturity of their helicopter platforms and we were stupid enough to believe them not once, but twice. Fortunately even we managed to wise up a third time and not get bitten again.Goverment at the time wanted a MOTS solution but If I remember correctly from the ANAO report was that at the time the US were introducing S70M as at that time it was still in devolpment variant of the Blackhawk family which one would have thought that even though it was still an in devolpment it really was just an evolution of the current in service airframe, we're as the NH90 had no pedigree to begin with.
Unfortunatly politics got involved what should have been a straight forward program. If the wanted enhanced capabilty should have gone Merlin EH101
Un-funnily enough the MH-60R is like to reach operational service well ahead of either Tiger or MRH-90 despite being ordered 5 years later...