I don't know how much capital bidders invest in other PFIs but I think we are talking big bucks that the loser will have forfeited - not only all the legwork going into preparing the bid but also a large deposit to secure the airframes on the production run at the factories of both Sikorsky and Eurocopter.
I understand that a major requirement of a PFI is to show value for money but since no-one was able or willing to establish what SAR is currently costing or would cost for 25 years retaining the present service providers, this would be difficult to achieve. A military solution was not allowed to be entered either so any legal challenge might hinge on whether the PFI process can be shown to be as squeaky clean as possible. If there are any errors in procedure then I am sure the lawyers will find them.