The Norwegian government is already involved in SAS, its flag carrier, along with 2 neighboring governments. Moreover its souvereign fund is public money invested for a positive return for the benefit of the country and its taxpayers.
On that basis I fail to see why Norwegian Air, as a private business and competitor, would benefit from the blind & unconditionnal support of its government.
As for the too big to fail argument, this one ignores what happened to Pan Am, TWA, Swissair, Sabena, Olympic or some others more recent or still to come.